This is the world's first 4-dimensional (hypercubic) crossword.
Within the grids shown above, 5-letter words run across and down as usual (clues below).
But the 5 grids within a given row can be stacked to make a cube, so there are also `through' clues, e.g. the word (1) `through' has its first letter in the top-left corner of the top-left grid, its second letter in the top-left corner of the second grid on the top row, and so on, with the fifth and last letter in the top-left corner of the fifth grid on the top row.
Similarly, there are `until' clues for words which run from grid to grid down the page e.g. (31) `until' has its first letter in the centre square of the rightmost grid of the top row and the remaining letters in the centre squares of the rightmost grids on the second, third, fourth and fifth rows.
The across, down, through and until directions are all mutually perpendicular, i.e. the crossword is a 4-dimensional hypercube measuring 5 by 5 by 5 by 5 by 5, with 54 = 625 cells in all.
The white `squares' or cells of the crossword accommodate 140 different 5-letter words, 35 running in each of the 4 directions across, down, through and until. The crossword is highly connected, with 4-word intersections taking place in 97 of the cells. On average, each 5-letter word is crossed by about 8.3 other words. Despite this, the words form two interlocking but independent crosswords, which share no letters.
Below are given two sets of clues - simple clues and cryptic clues. You can use either the simple clues or the cryptic ones (whichever you prefer) but note that they can't be mixed. E.g. 1 across in the simple clues doesn't clue the same word as 1 across in the cryptic clues.
Across
1) Discharged, luminously
4) Seal attached to a document
7) Sit again
14) Shaved
17) English
20) Dull
27) Separates with a toothed instrument
30) Punctuation mark
33) Band of mown grass
42) Identical
43) Asian country
46) Caribbean country
47) Greek wood-god
48) Type of salt
51) Parts of feet to which legs are articulated
54) Gowns
57) River in Argentina
60) Ownerless property found hidden
61) Italian noblewoman
62) Fibre obtained from Agave
65) Type of joint or hat
66) Little island
73) Steersman
74) Wild ox with shaggy hair
77) Woolly animal
78) Platform
79) Ancient port
82) Deputy doctor
85) Turns on an axis
88) In a pile
91) Abate
92) Game of chance
93) Frame for supporting picture
96) Obsolescent Indian coins
97) Flat thin circular bodies
Down
1) Yellowish fossil resin
2) Small rooms
3) Anything drawn
14) Liquid part of blood
15) Correct
16) Male honey-bee
27) Male birds
28) Mediterranean island
29) Coincidence in time
40) Sit upon the heels
41) Causing ruin or death
44) Type of canoe
45) Remains
48) Come in
49) Low woody plant
50) Posts
57) Marked
58) Deep moan
59) Greek letter
62) Feet of two syllables
63) Whole
64) Turn out
71) Copy
72) That which gives motion
75) Very large mammal
76) Fruit
79) Of the sun
80) Pertaining to a duke
81) Provinces of ancient Egypt
88) Girl's name
89) Ant (arch.)
90) Courtyard
93) South African antelope
94) Masses of rock-grains
95) Endures
Through
1) Savoury meat jelly
2) Type of stroke in billiards
3) Extinct birds
4) French mountain
5) Allowed
6) Fruit of a tree of the beech family
7) Covers with hoar-frost
8) Sanskrit book of aphorisms
9) Prongs
36) Young pigeon
37) Flavour
38) Small party united for some secret design
39) Outer covering of a flower
48) Languor
49) Spectacle
50) Elk
51) Symbol receiving superstitious respect
52) Perch
53) Girl's name
54) Spokes
55) Commonplace
56) Sparing
67) Tenth part
68) Nectar
69) Clock faces
70) One who gives
79) Dull dark blue
80) Adorn
81) Asian country
82) Immature animal differing markedly from adult
83) Umbelliferous plant whose seeds are used as carminatives
84) An unscientific division of Lepidoptera
85) Governed
86) Slips of wood
87) Blots
Until
1) States with conviction
2) Boxed
3) Evil spirit
4) Nut chewed in the East
5) Effusive, songlike
6) Self-evident truth
7) More unusual
8) Girl's name
9) Examines
10) Ten-armed cephalopod
11) North German
12) Insipid
13) Man of great wealth
14) Himalayan animal
15) Rascal
16) Hang down
17) Star
18) Tend a horse
19) Public
20) Small representation
21) Belief
22) One of the Muses
23) Hiding place
24) Hard metal
25) Bird of prey
26) Region of Austria
27) Illegal act
28) Old Flemish coins
29) Gain by contrivance or theft
30) Punctuation mark
31) Ancient language
32) Requirements
33) Watched, observed
34) Book of maps
35) Dislikes intensely
Across
1) Ice chips on snake jelly
4) Boredom brings on small sounds
7) Give bad press to rock bands
14) Cannon ball, from Maroc
17) It's observed by the guide
20) Circle of theatre clothes
27) Double act south of old Mauritius
30) A thousand eyes see some deer
33) Alpen, not plane
42) Pigeon starts to wrangle
43) It goes back to the church
46) Make sense of state?
47) Sweet flower promised to Israelites
48) Mountain of snow?
51) Pole with roots in North America?
54) It doesn't appear to take after its parents
57) OK in Galle
60) King rings good chap for winged things
61) Spice with Indian morsel
62) Oak
65) Peace goddess points in anger
66) Fly-by-nights with a light touch?
73) Clifford and Buckingham and like-minded
74) Faces behind hands
77) Bud's protector made clay by ray
78) Spaniard or philanthropist
79) Freezes breezes
82) More than one spoke of bones
85) King fought duel and got the upper hand
88) Art we reflect as aphorisms
91) Bachelor not available - left for flat
92) Slips over the wall
93) Opposition saw projections
96) Little little time to mean little
97) Leopard identifies blots in TV advertising
Down
1) Raves about states, with conviction
2) Pear pare and a rare bear
3) Wrong sheik up for century
14) Boxed about, like Edward
15) Goldback Guelph cuts ruffian
16) Times change for little people
27) Of my diable?
28) Decline Dr. No's soft rendering
29) Slate suffering creep
40) Point to tobacco sucker being well-armed
41) Seal almost hidden
44) Saxophone quartet with North German
45) Metal brace
48) Stake the Spanish nut
49) Christmas star?
50) Punctuation for 1000100010001
57) Music of old harp
58) Great opening for the husband of the future
59) Bend a can of tongue for the masses
62) Across the island, in principle
63) Public, over the top
64) Born and dies, first and last wishes
71) Dull vapour, 50% iodine and deuterium
72) Gold for high flyer
75) Indian prince partly naked before Robert
76) Beginner learning in Austria
79) Juicier subjects Art and English spice the 3 R's
80) Small is beautiful
81) Saw over the frontier
88) She saw a future in easy billiards
89) Belief upheld
90) Morocco-bound book
93) Examines shells
94) Time to muse
95) Dislikes haste?
Through
1) Arched, sparingly
2) Cut pear dies first
3) Bristles may be cleaned with their teeth!
4) Poems about Derby
5) Black one growing in the middle
6) Fibre let go by nine in Rome
7) Do evil outside old port
8) A male ape loses his tail in a pile-up
9) Lease to run out for artists
36) Like quality?
37) Tahiti, after losing leader, relocates in Caribbean
38) Model story about me
39) It follows, in a woolly sort of way
48) Seal a seal?
49) A long translation into English
50) Gutsy explorer
51) Stair twists ankles
52) Hidden wealth of monarch
53) Joint cover for archbishops
54) He heals body or soul, instead of another
55) Relax while time runs backwards
56) Karenina's no longer current
67) Rising sun to bring out the shine
68) Perched with younger demon
69) Shaggy American reveals French stereo?
70) Approximately the opposite of roof
79) Second attempt to settle or score
80) Substance, almost dull
81) What's new on the lawn?
82) Get up sober, perhaps
83) Lady
84) Rock's rented
85) For those with bread?
86) Much to gamble
87) Like coins cast by the Greeks
Until
1) Ready for old fly trap
2) Blood sample, skimmed and stirred
3) They stop the flow and start the day
4) Come in to open territory
5) Marked denial from the editor
6) I'm 2 feet short and long
7) Radiant, like the sun
8) She's sprung by Spring
9) South African in eastern land
10) Sitting tenancy?
11) Canoeonac
12) Copy note twice to Cuban capital
13) Good time for big diver
14) Monks live in them (and vice versa!)
15) Just a hand
16) Kind of liquor on a small island
17) Brush?
18) Sound of discomfort from Gormenghast
19) To tally
20) Nobleman's chewing the cud with Alex
21) Insect - sound of 1000 brought together
22) Of deserts and sun-drenched beaches
23) Destined to kill
24) Stops guys
25) Machine with rotor on the outside
26) Fruit (anag.)
27) Order sketch
28) Hum bum
29) Keeping good time with the Swiss
30) Chain letters?
31) O O 1000000
32) Turnout makes egghead green
33) Names unclear for Egypt's lands
34) Courtyard proportion trimmed
35) Cargoes of artificial feet
The cryptic clues mostly adhere to the usual conventions, but purists may note the occasional exuberant departure from strict Ximeneity (Ximenes was the cryptic-crossword-setter for the Observer, exemplar of the art).
Typesetting note: the clues to 62 across and 83 through are in small and italic fonts respectively (some browsers/printers may not support this).
This crossword (no. 65 in my series) was originally published in 1989 in 'Gemini' (the newsletter of the Royal Greenwich Observatory), issue 24, p.14, and then in the May 1990 edition of 'Crossword'.
The words used can be found in standard references.
The solution is available on request.
Useful links to information about 4D and higher dimensions: