The Staircase

5×5×5 · 27 entries

Grids — one sheet per Z layer

Z 1

123
456
789

Z 2

Z 3

101112
13
141516

Z 4

Z 5

171819
20
21

A square marked also carries a letter of a Through answer running through the sheets.

Clues

Across

1Tubes the Scotsman blows into (5)
4Dubious, and out of the sun (5)
7Notes arranged in rock (5)
10The detective's work, or the luggage (5)
13A rope twisted into drama, with singing (5)
14Lends a hand with the LPs, oddly (5)
17Delta rearranged — that is how the cards went (5)
20The writer's own subject (5)
21Haste rearranged into loathing (5)

Down

1Sends off, or what the goal stands on (5)
2Instrument to be played quietly (5)
3Manner that sounds like a way over a fence (5)
10Fabric, and the clergy (5)
11A charm, or a stint (5)
12Washes, and what is on in the afternoon (5)
17Sharing the bill, and from the Low Countries (5)
18Later, when shuffled, turns watchful (5)
19Difficult years hidden in canteens (5)

Through

4Thus written, as found in music (3)
5The gym-goer's midriff, briefly (3)
6Agreement found in eyesight (3)
7Words rearranged into a blade (5)
8Nothing huge — and the very last of it (5)
9Precise, or demand with menace (5)
14Something worn, found in what (3)
15Shelter from the wind, or a general (3)
16A woman found in ashes (3)