diff --git a/docs/architecture/cover-art.md b/docs/architecture/cover-art.md
index 322b5b18..1222eaf4 100644
--- a/docs/architecture/cover-art.md
+++ b/docs/architecture/cover-art.md
@@ -81,7 +81,7 @@ cover can never be scrolled past, and `coverView` then gives the art every row t
 above it did not use. A list too short for even the floor keeps the divider and skips the
 art — the hint is worth more than a smear.
 
-`x` lifts the cover (`coverPeeked`) and puts it back; the divider carries the hint and the
+`z` lifts the cover (`coverPeeked`) and puts it back; the divider carries the hint and the
 hidden count, where the web app puts its buttons. Setting a cover closes it, so a box
 arrives covered rather than however the last one was left. Only the Imbox is coverable —
 that is haystack's rule (`Box::Imbox#coverable?`), and it is the same box that gets the
diff --git a/docs/tui.md b/docs/tui.md
index ba03a94c..22045222 100644
--- a/docs/tui.md
+++ b/docs/tui.md
@@ -61,7 +61,7 @@ uppercase belongs to Labels:
 | `t` | trash — every selected thread when any are selected, otherwise the one under the cursor. Not offered when it would target a bundle |
 | `!` | mark as spam |
 | `-` / `+` | ignore / stop ignoring |
-| Space | select the thread for a bulk action (`e`, `u`, `t` or Ctrl+B) |
+| Space or `x` | select the thread for a bulk action (`e`, `u`, `t` or Ctrl+B) |
 | Escape | clear the selection |
 | Ctrl+B | preview every bulk-reply recipient, then write one reply to every selected thread |
 | Ctrl+U | recall a delayed bulk reply while HEY's undo window is open |
@@ -193,7 +193,7 @@ preview only reads the email; it doesn't screen the sender or tell them anything
 The Imbox can wear cover art, the way the HEY web app does: everything you have already
 read goes under it, so the box ends at what still wants your attention instead of trailing
 off into a month of receipts. The divider stays and says how much is under there — press
-`x` to peek, `x` again to close it, or `9` to open Previously Seen on its own screen.
+`z` to peek, `z` again to close it, or `9` to open Previously Seen on its own screen.
 
 Press Ctrl+V to choose one: `blobs`, `grid`, `peace`, `terrazzo`, `topo` or `waves`, the
 same six covers redrawn as characters, so they work in any terminal rather than only the
diff --git a/internal/tui/bulk_reply.go b/internal/tui/bulk_reply.go
index 8af2c226..a31afe79 100644
--- a/internal/tui/bulk_reply.go
+++ b/internal/tui/bulk_reply.go
@@ -287,7 +287,7 @@ func replyNoun(count int) string {
 func (v *mailView) startBulkReply() tea.Cmd {
 	postingIDs := v.actionList().selectedIDs()
 	if len(postingIDs) == 0 {
-		v.notice = "Select threads with space before starting a bulk reply"
+		v.notice = "Select threads with space or x before starting a bulk reply"
 		return nil
 	}
 	requestID, ctx := v.requests.begin(v.vc.ctx, mailRequestBulkReply)
diff --git a/internal/tui/bulk_reply_test.go b/internal/tui/bulk_reply_test.go
index 5c39e62c..c70f62f1 100644
--- a/internal/tui/bulk_reply_test.go
+++ b/internal/tui/bulk_reply_test.go
@@ -120,7 +120,7 @@ func TestTUIBulkReplyRequiresExplicitSelection(t *testing.T) {
 	if cmd := view.HandleContentKey(keyPress("ctrl+b")); cmd != nil {
 		t.Fatal("bulk reply without a selection should not make a request")
 	}
-	if view.notice != "Select threads with space before starting a bulk reply" {
+	if view.notice != "Select threads with space or x before starting a bulk reply" {
 		t.Errorf("notice = %q", view.notice)
 	}
 	if requests := state.snapshot(); len(requests) != 0 {
diff --git a/internal/tui/calendar_views.go b/internal/tui/calendar_views.go
index 793d91cd..dbcb551d 100644
--- a/internal/tui/calendar_views.go
+++ b/internal/tui/calendar_views.go
@@ -650,7 +650,7 @@ func renderDayView(events, habits, countdowns []Recording, anchor, now time.Time
 
 	// The day names itself above its hours — the subnav carries the calendar and the
 	// view mode, so which day this is has nowhere else to be said — and the keys that
-	// move it sit on the same line, where the cover puts "x to peek".
+	// move it sit on the same line, where the cover puts "z to peek".
 	b.WriteString(hintedSectionHeader(anchor.Local().Format("Monday, January 2"), hint, width))
 	b.WriteString("\n")
 
diff --git a/internal/tui/content.go b/internal/tui/content.go
index 485b10b6..16c4699b 100644
--- a/internal/tui/content.go
+++ b/internal/tui/content.go
@@ -721,7 +721,7 @@ func (c *contentList) view() string {
 
 		if label := c.sectionLabelAt(i); label != "" {
 			if c.cover != coverNone && sectionOf(p) == sectionPreviouslySeen {
-				fmt.Fprintln(&b, hintedSectionHeader(label, "x to cover", c.width))
+				fmt.Fprintln(&b, hintedSectionHeader(label, "z to cover", c.width))
 			} else {
 				fmt.Fprintln(&b, sectionHeader(label, c.width))
 			}
@@ -850,7 +850,7 @@ func (c *contentList) view() string {
 // The threads themselves are not rendered at all — that is the whole point of a
 // cover, and it is why the art can have every row the postings did not use.
 func (c *contentList) coverView(hidden, rowsUsed int) string {
-	hint := fmt.Sprintf("%d hidden · x to peek", hidden)
+	hint := fmt.Sprintf("%d hidden · z to peek", hidden)
 	header := hintedSectionHeader(sectionPreviouslySeen.label(), hint, c.width)
 
 	rows := c.height - rowsUsed - 1
@@ -871,7 +871,7 @@ func sectionHeader(label string, width int) string {
 }
 
 // hintedSectionHeader is a section label with a hint on its right, where the HEY web
-// app puts a section's buttons: "Previously Seen ──── 34 hidden · x to peek", or
+// app puts a section's buttons: "Previously Seen ──── 34 hidden · z to peek", or
 // "Habits ──── b to manage".
 func hintedSectionHeader(label, hint string, width int) string {
 	rule := lipgloss.NewStyle().Foreground(colorChrome)
diff --git a/internal/tui/cover_picker.go b/internal/tui/cover_picker.go
index fe30369d..9e8a5745 100644
--- a/internal/tui/cover_picker.go
+++ b/internal/tui/cover_picker.go
@@ -95,7 +95,7 @@ func (p *coverPicker) view(styles styles, width int) string {
 		b.WriteString(preview + "\n\n")
 	}
 	b.WriteString(strings.Join(wrapText(
-		"A cover hides the threads you have already read. Press x to look under it.",
+		"A cover hides the threads you have already read. Press z to look under it.",
 		contentWidth), "\n"))
 	return b.String()
 }
diff --git a/internal/tui/covers_test.go b/internal/tui/covers_test.go
index 79d438b6..8f087805 100644
--- a/internal/tui/covers_test.go
+++ b/internal/tui/covers_test.go
@@ -556,7 +556,7 @@ func TestCoverHidesPreviouslySeen(t *testing.T) {
 	if !strings.Contains(view, sectionPreviouslySeen.label()) {
 		t.Error("covered list dropped the Previously Seen divider")
 	}
-	if !strings.Contains(view, "3 hidden · x to peek") {
+	if !strings.Contains(view, "3 hidden · z to peek") {
 		t.Error("covered list gave no hint about what is under the cover")
 	}
 	for _, posting := range list.postings[1:] {
@@ -599,7 +599,7 @@ func TestPeekingLiftsTheCover(t *testing.T) {
 	if !strings.Contains(view, list.postings[2].Name) {
 		t.Error("peeking did not reveal the seen threads")
 	}
-	if !strings.Contains(view, "x to cover") {
+	if !strings.Contains(view, "z to cover") {
 		t.Error("a peeked list does not say how to put the cover back")
 	}
 
@@ -627,7 +627,7 @@ func TestCoverDropsTheArtBeforeTheDivider(t *testing.T) {
 	list := coveredList(coverTopo, coverMinRows+2, false, false, true)
 
 	view := list.view()
-	if !strings.Contains(view, "1 hidden · x to peek") {
+	if !strings.Contains(view, "1 hidden · z to peek") {
 		t.Error("a short covered list lost its divider")
 	}
 	if rows := strings.Count(view, "\n") + 1; rows > coverMinRows+2 {
@@ -643,7 +643,7 @@ func TestCoverWithNothingUnread(t *testing.T) {
 		t.Errorf("itemCount = %d, want 0", got)
 	}
 	view := list.view()
-	if !strings.Contains(view, "2 hidden · x to peek") {
+	if !strings.Contains(view, "2 hidden · z to peek") {
 		t.Error("an all-read Imbox does not say what is under the cover")
 	}
 	if rows := strings.Count(view, "\n") + 1; rows != 20 {
diff --git a/internal/tui/mail.go b/internal/tui/mail.go
index 3f6c94a6..701aa49c 100644
--- a/internal/tui/mail.go
+++ b/internal/tui/mail.go
@@ -1110,7 +1110,7 @@ func (v *mailView) HelpBindings() []helpBinding {
 		}
 		bindings := []helpBinding{
 			{"enter", "open"},
-			{"space", "select"},
+			{"space/x", "select"},
 			{"ctrl+b", "bulk reply"},
 			{"r", "reply"},
 			{"f", "forward"},
@@ -1148,7 +1148,7 @@ func (v *mailView) HelpBindings() []helpBinding {
 		{"/", "search"},
 		{"ctrl+s", "screener"},
 		{"c", "compose"},
-		{"space", "select"},
+		{"space/x", "select"},
 		{"ctrl+b", "bulk reply"},
 		{"r", "reply"},
 		{"f", "forward"},
@@ -1172,9 +1172,9 @@ func (v *mailView) HelpBindings() []helpBinding {
 		helpBinding{"ctrl+r", "reload"},
 	)
 	if v.postingList.cover != coverNone {
-		peek := helpBinding{"x", "peek under cover"}
+		peek := helpBinding{"z", "peek under cover"}
 		if v.postingList.coverPeeked {
-			peek = helpBinding{"x", "cover"}
+			peek = helpBinding{"z", "cover"}
 		}
 		bindings = append(bindings, peek)
 	}
@@ -1505,7 +1505,7 @@ func (v *mailView) HandleContentKey(msg tea.KeyPressMsg) tea.Cmd {
 			case "j":
 				v.seenList.moveDown()
 				return v.loadMoreSeenPostings()
-			case " ", "space":
+			case " ", "space", "x":
 				v.seenList.toggleSelected()
 				return nil
 			case "ctrl+b":
@@ -1559,7 +1559,7 @@ func (v *mailView) HandleContentKey(msg tea.KeyPressMsg) tea.Cmd {
 			return v.startSearch()
 		case "c":
 			return v.startCompose()
-		case " ", "space":
+		case " ", "space", "x":
 			v.postingList.toggleSelected()
 			return nil
 		case "ctrl+b":
@@ -1581,7 +1581,7 @@ func (v *mailView) HandleContentKey(msg tea.KeyPressMsg) tea.Cmd {
 				return nil
 			}
 			return v.startCollectionPicker()
-		case "x":
+		case "z":
 			v.postingList.toggleCoverPeek()
 			return nil
 		case "ctrl+v":
@@ -3025,7 +3025,7 @@ func (v *mailView) selectionHelpBindings(selected int) []helpBinding {
 		bindings = append(bindings, helpBinding{"t", "trash"})
 	}
 	bindings = append(bindings,
-		helpBinding{"space", "toggle"},
+		helpBinding{"space/x", "toggle"},
 		helpBinding{"esc", "clear"},
 		helpBinding{"ctrl+b", "bulk reply"},
 	)
diff --git a/internal/tui/mail_selection_test.go b/internal/tui/mail_selection_test.go
index 56db0107..d7caf747 100644
--- a/internal/tui/mail_selection_test.go
+++ b/internal/tui/mail_selection_test.go
@@ -401,7 +401,7 @@ func TestMailViewHelpBarOffersOnlyTheSelectionActions(t *testing.T) {
 	if !strings.Contains(bindings[0].key, "2 selected") || bindings[0].desc != "" {
 		t.Errorf("first binding = %+v, want the selected count", bindings[0])
 	}
-	for _, key := range []string{"e", "u", "t", "space", "esc", "ctrl+b"} {
+	for _, key := range []string{"e", "u", "t", "space/x", "esc", "ctrl+b"} {
 		if !hasHelpBinding(bindings, key) {
 			t.Errorf("help bar is missing %q: %v", key, bindings)
 		}
diff --git a/internal/tui/mail_test.go b/internal/tui/mail_test.go
index 82c01503..5fec82c9 100644
--- a/internal/tui/mail_test.go
+++ b/internal/tui/mail_test.go
@@ -11,6 +11,7 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"path/filepath"
+	"regexp"
 	"slices"
 	"strconv"
 	"strings"
@@ -3487,16 +3488,144 @@ func TestMailViewHaystackPickerAliases(t *testing.T) {
 	}
 }
 
-func TestMailViewCoverPeekUsesX(t *testing.T) {
+func TestMailViewCoverPeekUsesZ(t *testing.T) {
 	v := mailWithPostings()
 	v.postingList.setCover(coverTopo)
-	v.HandleContentKey(keyPress("x"))
+	v.HandleContentKey(keyPress("z"))
 	if !v.postingList.coverPeeked {
-		t.Fatal("x did not lift the cover")
+		t.Fatal("z did not lift the cover")
+	}
+	v.HandleContentKey(keyPress("z"))
+	if v.postingList.coverPeeked {
+		t.Fatal("z did not replace the cover")
+	}
+}
+
+// x selects like space does, matching the HEY desktop app — including on a covered
+// Imbox, where x used to lift the cover (that is z's key now).
+func TestMailViewSelectsWithXLikeSpace(t *testing.T) {
+	v := mailWithPostings()
+	v.postingList.setCover(coverTopo)
+
+	v.HandleContentKey(keyPress("x"))
+	if ids := v.postingList.selectedIDs(); len(ids) != 1 || ids[0] != 100 {
+		t.Fatalf("selected after x = %v, want [100]", ids)
+	}
+	if v.postingList.coverPeeked {
+		t.Error("x lifted the cover instead of selecting")
+	}
+	v.HandleContentKey(keyPress("x"))
+	if ids := v.postingList.selectedIDs(); len(ids) != 0 {
+		t.Errorf("selected after second x = %v, want none", ids)
+	}
+
+	seen := mailWithPostings()
+	seen.seenActive = true
+	seen.seenList.setPostings(testPostings())
+	seen.HandleContentKey(keyPress("x"))
+	if ids := seen.seenList.selectedIDs(); len(ids) != 1 || ids[0] != 100 {
+		t.Errorf("seen screen selected after x = %v, want [100]", ids)
+	}
+}
+
+func TestMailViewSeenScreenXDeselectsWithoutLeaving(t *testing.T) {
+	v := mailWithPostings()
+	v.seenActive = true
+	v.seenList.setPostings(testPostings())
+
+	v.HandleContentKey(keyPress("x"))
+	if ids := v.seenList.selectedIDs(); len(ids) != 1 || ids[0] != 100 {
+		t.Fatalf("seen screen selected after x = %v, want [100]", ids)
 	}
 	v.HandleContentKey(keyPress("x"))
+	if ids := v.seenList.selectedIDs(); len(ids) != 0 {
+		t.Errorf("seen screen selected after second x = %v, want none", ids)
+	}
+	if !v.seenActive {
+		t.Error("x left the Previously Seen screen")
+	}
+}
+
+func TestMailViewSelectionHelpNamesEveryToggleKey(t *testing.T) {
+	v := mailWithPostings()
+	v.HandleContentKey(keyPress("x"))
+
+	var toggle string
+	for _, binding := range v.HelpBindings() {
+		if binding.desc == "toggle" {
+			toggle = binding.key
+		}
+	}
+	if toggle != "space/x" {
+		t.Fatalf("selection help toggle key = %q, want %q", toggle, "space/x")
+	}
+	for _, step := range []struct {
+		key  string
+		want int
+	}{{" ", 0}, {" ", 1}, {"x", 0}} {
+		v.HandleContentKey(keyPress(step.key))
+		if ids := v.postingList.selectedIDs(); len(ids) != step.want {
+			t.Fatalf("selected after %q = %v, want %d", step.key, ids, step.want)
+		}
+	}
+}
+
+// The peek works on a list with a selection standing, and leaves the selection alone:
+// lifting the cover changes what is shown, not what a bulk action will act on.
+func TestMailViewCoverPeekKeepsTheSelection(t *testing.T) {
+	v := mailWithPostings()
+	v.postingList.setCover(coverTopo)
+	v.HandleContentKey(keyPress("x"))
+
+	for _, wantPeeked := range []bool{true, false} {
+		v.HandleContentKey(keyPress("z"))
+		if v.postingList.coverPeeked != wantPeeked {
+			t.Fatalf("coverPeeked after z = %v, want %v", v.postingList.coverPeeked, wantPeeked)
+		}
+		if ids := v.postingList.selectedIDs(); len(ids) != 1 || ids[0] != 100 {
+			t.Fatalf("selected after z = %v, want [100]", ids)
+		}
+	}
+}
+
+// Every place that tells the reader how to look under the cover names the key that
+// does it: the cover picker's footer, the help bar, and the divider either way round.
+func TestMailViewCoverHintsNameThePeekKey(t *testing.T) {
+	footer := regexp.MustCompile(`Press (\S+) to look under it`).FindStringSubmatch(newCoverPicker(coverTopo).view(newStyles(), 120))
+	if footer == nil {
+		t.Fatal("cover picker does not name the peek key")
+	}
+	key := footer[1]
+
+	list := coveredList(coverTopo, 20, false, true)
+	if hint := regexp.MustCompile(`hidden · (\S+) to peek`).FindStringSubmatch(ansi.Strip(list.view())); hint == nil || hint[1] != key {
+		t.Errorf("covered divider hint = %v, want %q", hint, key)
+	}
+	list.toggleCoverPeek()
+	if hint := regexp.MustCompile(`(\S+) to cover`).FindStringSubmatch(ansi.Strip(list.view())); hint == nil || hint[1] != key {
+		t.Errorf("peeked divider hint = %v, want %q", hint, key)
+	}
+
+	v := mailWithPostings()
+	v.postingList.setCover(coverTopo)
+	if !hasHelpBinding(v.HelpBindings(), key) {
+		t.Errorf("help bar does not offer %q for the peek: %+v", key, v.HelpBindings())
+	}
+	v.HandleContentKey(keyPress(key))
+	if !v.postingList.coverPeeked {
+		t.Fatalf("%q, the key the picker names, did not lift the cover", key)
+	}
+	if ids := v.postingList.selectedIDs(); len(ids) != 0 {
+		t.Errorf("the peek key selected %v", ids)
+	}
+	for _, binding := range v.HelpBindings() {
+		if binding.desc == "cover" && binding.key != key {
+			t.Errorf("help bar puts the cover back with %q, want %q", binding.key, key)
+		}
+	}
+	v.HandleContentKey(keyPress(key))
 	if v.postingList.coverPeeked {
-		t.Fatal("x did not replace the cover")
+		t.Errorf("%q did not put the cover back", key)
 	}
 }
 
@@ -4563,7 +4692,7 @@ func TestMailViewSeenScreenHelpOffersTheThreadActions(t *testing.T) {
 	v.seenActive = true
 
 	bindings := v.HelpBindings()
-	for _, key := range []string{"enter", "space", "ctrl+b", "a", "l", "u", "t", "v", "b", "n"} {
+	for _, key := range []string{"enter", "space/x", "ctrl+b", "a", "l", "u", "t", "v", "b", "n"} {
 		if !hasHelpBinding(bindings, key) {
 			t.Errorf("seen screen help misses %q: %+v", key, bindings)
 		}