The WyrmholeBack to round

Endless Knots

by Nishant Pappireddi and Olga Vinogradova

Answer:
PICO

The clues are presented as infinitely scrolling and the given integers p and q are coprime. This along with the title “Endless Knots” hints towards the main twist (pun intended) of the puzzle. Each list of clues should be associated with a torus knot defined by the (p,q) values.

A torus knot is usually a 3D shape. However in this case each set of clues forms what is arguably a diagramless crossword where the grid is a 2D representation of the torus knot. Concatenated answers to the clues weave through each other around the grid and therefore this string of letters has no beginning nor end (hence the presentation). The Example set provides a playground to experiment with how to fill a grid on a small scale. Two clues are bolded. Reading them tells us that in order to complete a grid, we need to FILL BLANKS with one letter per blank in the torus knot diagram.

A sketch of the filling pattern from an arbitrary starting point is shown below using the torus knot grid from the first subpuzzle. We can read answers to clues from the cells this line passes through. The outside and inside edges always contain unchecked letters and everything in between contains checked letters. Since all word lengths are given, these properties may be used to logically deduce positions of letters in a grid.

Grid path

There are two things to extract from each grid. One is an unchecked letter where the “? (1)” clue appears in each list. The other is a word or phrase. The extraction gimmick for the latter is clued by the title of each subpuzzle. In all but Example and Edged Case this gimmick is also required to correctly fill the grid.

The single letters together yield an answer parsed as READ AS SI. But what do we read as an SI metric? Indexing (p,q) into the extracted word or phrase and parsing in column major order yields TEN NEG TWELVE. This is a metric SI prefix which is the final answer: PICO.

A table summarizing the extraction and fill gimmicks is below:

NamepqFill and extraction gimmickAnswerIndex pIndex q“? (1)” clue(s)
Edged Case711Read letters on the outside or inside edge (depending on how the grid was constructed).INFINITESETTTR
Twisted Trio57There are enough clues to fill the grid thrice. Take the overlapping letters from each subsequent pair of grid fills. SPIDERWEBEWEAD
Missing Halves611Three of the clues give answers that don’t fit in the blanks or the enumeration. The enumeration is for only half the answer. Take the halves that don’t fit and read clockwise around the filled grid.HERRINGBONENEA
desreveR712Two of the answers must be filled in backwards. E.g. if all clues are being filled clockwise, these two must be counter-clockwise.NUTRIENTCYCLENLS
Double Trouble79Five cells must be filled with two letters to make the rest fit. Read the bigrams.INTERWEAVEEVS
Differing Opinions911Letters in eleven of the cells conflict with their woven overlaps. Take their difference and A1Z26.DISENTANGLEGEI

Appendix

Here are some notes on generating the grids.

In the mathematical sense a torus knot of (p,q) is equivalent to one of (q,p). Depending on where one looks up the parameterization to draw the knots these two values are sometimes inconsistently labeled. This puzzle uses the notation that appears on the wikipedia page and also through querying Wolfram Alpha. Here is a simple Python script to generate a torus knot diagram.

The filled torus knot diagrams, completed lists of clues, and any further subpuzzle extraction details are given below. Single letter extraction is marked in blue. Clues relevant to the subpuzzle extraction are marked in red. All grids here are filled clockwise.

Example (p=5;q=4)

Filled grid for Example

Boundaries between words are marked with a bold line.

AnswerLengthClue
LEG3A lower body appendage, you have two of them
LAW3___ and Order
KITE4Something you can fly on a windy day
BEAN4It could sprout into a stalk
FILL4When you eat well you might eat your ____
BLANKS6Training bullets

Edged Case (p=7;q=11)

Filled grid for Edged Case

Answer is extracted from the outside edge. However it is also possible to fill this knot such that the final answer appears on the inside edge. There is no way to mark where to start reading the answer, however only one starting position gives an answer that is vaguely thematic to the puzzle.

AnswerLengthClue
ONESIE6Infant garment
ETC3List ender, abbr.
ON2Off's opposite
TEA3Hot leaf juice
SPADE5Gardening tool
SCION5Descendant or heir
URGE4Craving
R1?
TAINT5Sully
BUMP4This slows down cars on the road
SEAT4An elected position
CHIPS5Potato-based snacks, in both the US and UK
RIO3River in Spain or Portugal
ANA3Former World No. 1 Ivanovic
OTAKU5Someone who likes anime and/or manga
SOW3Female pig
EASTER6Egg or island preceder
PUS3Fluid in infected tissue
FIAT4Unbacked currency
CASA4House in Spanish
BARS4Places to drink or measures in music
WEEP4Willows might do this sadly
REIN4Keep under control
EFFORT6Conscious exertion of power
LATTE5Espresso and steamed milk
EROS4Greek god of love
DEPTH5The fathom measures this

Twisted Trio (p=5;q=7)

Filled grids for Twisted Trio

Unlike the other subpuzzles, these three grids must have a “beginning” and “end” to each fill. The boundary between the grids is marked by the bold line. The first grid starts with PIER and ends with ILL, second is PIT to RULER, third is ADHD to SHY. This also allows the grid fills to be overlaid on top of each other. Subsequent overlapping letters give answer substrings. The leftmost grid has the word ONE as part of the fill. Using this grid first we get a reading order for both the subpuzzle answer and the single letter extracts.

AnswerLengthClue
PIER4____ 39, in San Francisco
NOPE4A red negation card in Exploding Kittens
REBEL5Someone who resists authority
SUIT4Hearts or diamonds, for example
ONE3In set theory, this can be defined as the set containing the empty set
NEWT4An eye of this is favored by witches for potions
BIAS4Unfairly influence
PETRA5Nabataean capital
E1?
POWER5Work over time
ILL3Sick
PIT3Hole or cavity
DENT4Light damage on a car
GORY4Bloody
MESH4Material in screen door
IDLE4Inactive
RIGA4Latvian port city
XYLO4Prefix meaning "wood"
SPUD4Informal term for potato
DIRTY5Filthy
A1?
RULER5Straightedge with marks
ADHD4Neurodevelopmental condition, abbr.
EYES4Visual organs
DEBT4Opposite of credit
HEN3Rooster's mate
D1?
AVERT5Stave off a crisis
SWAB4Tool in COVID test kit
SPEAK5To utter words
ADORE5Admire and love
AWED4Filled with wonder
SHY3What someone might be around their crush

Missing Halves (p=6;q=11)

Filled grid for Missing Halves

Take the second halves of the clues FAT|HER, COVE|RING, and WISH|BONE and read clockwise. Again only one starting position gives an answer that makes sense.

AnswerLengthClue
SMACK5Loud kissing sound
DODGE5Evade
IRON4Magnetic metal
HARP4Instrument associated with angels
AFAR4At a distance
AMINO5Type of acid that makes up proteins
DORA4Child explorer with Boots
EASY4Lowest difficulty level, typically
NEON4Lights found in a bar
PARA4Prefix indicating a functional group directly opposite on a benzene ring
ROMAN5French novel
IVORY5Ebony's partner
WISHBONE4This is broken in half at Thanksgiving
AHOY4Originally suggested telephone greeting
YARN4Fiction, if you spin it maybe
TAME4Not wild
COVERING4An awning for example
DAWN4Ash's Sinnoh companion
RYAN4American Idol host Seacrest
A1?
NYE3The science guy
FATHER3Male parent, formally

desreveR (p=7;q=12)

Filled grid for desreveR

AnswerLengthClue
MONEY5This can be used to exchange for goods and services
SWAP4To exchange
LYRE4Harp ancestor
HIND4Rear (of a body part)
OUTCAST7Pariah
TOTE4Type of bag
S1?
TORPID6Lethargic, such as during hibernation
ACHE4Pain in head or back
LIEU4Stead
ORBIT5Equivalence class of group action
ROAM4Leave a phone's service area
SEWN4Made with thread and needle
MICRO5Prefix represented by mu
VELDT5African grassland
SONAR5ASDIC was an early version of this
TRUTH5The alternative to dare
YEAR42023, for example
CYCLE5A periodic sequence
SILVER6Metal commonly associated with runners-up
NUTRIENT8Protein or vitamin
META4Puzzle type that might show up at the end of a round
AMP3Unit of electric current
DYE3Food coloring
VOLVO5Car brand which means "I roll" in Latin
SOREST6Most in need of a massage

Double Trouble (p=7;q=9)

Filled grid for Double Trouble

The realization that there must be five bigrams may be reached by counting the enumerations of the given clues and the number of blank spaces in the knot diagram.

AnswerLengthClue
RHINO5Animal typically poached for its horn
SEPTA5Organization that runs public transit in some parts of Pennsylvania
PRY3Be nosy
LEAVE5A break from service
UVEA4Layer where iris is located
HUE3Variety of a color
STEP4Part of a ladder
AIRWAY6The A in ABC, in medicine
MADEUP4 2Like everything inWhose Line Is It Anyway
OPINE5Give one's viewpoint
FIR3Christmas tree, perhaps
TIP3Gratuity to one's server
ATLAS5Book of maps
SAVE4Functionality associated with the floppy disk icon
OSMOSIS7Gradual assimilation of knowledge
EARWAX6You might try to remove this with a Q-tip
READ4Type of receipt
S1?
CLAP4Sound that requires two hands
MASTER6To achieve proficiency in a skill
EXPAT5Person who resides in a foreign country, for short
REVEAL6Divulge

Differing Opinions (p=9;q=11)

Filled grid for Differing Opinions

In this grid, pink letters are always part of words that are read from inside to outside. Orange letters are part of words that read out to in. The pink letters are always bigger than the orange letters and the difference between them reads the answer.

AnswerLengthClue
LYS3Main tributary of the Scheldt
SNOUT5Pig's nose
ANTS4Nest workers
FISH4This word can be creatively spelled "ghoti"
EDIT4Revise before publication
POINT5Intersection of two distinct lines
STAR4Feature in a film
PISS4To urinate
TON3A metric weight
ANODE5Negative terminal
CARD4Ask for someone's ID
EARS4Aural appendages
GURU4Spiritual teacher
SUSHI5California rolls, for example
EXCEL5Microsoft product which confuses things for dates
GPS3Navigation aid, abbr.
NEST4Avian home
FAN3A big one may be rabid
CANDY5American sweets
ONYX4Banded quartz
EPIC4Long poem whose subject is usually one of legend
I1?
DEN3Lair
AESOP5Author of fables
CITES5Uses as a source
FERN4Non-flowering plant
VOLT4Unit of electric potential
EDDY4Small swirl
OTTO4Ideal thermodynamic internal combustion cycle
BRAND5Mark with an iron poker
TREE4A connected graph with a unique path between any two points
HOPE4Desire for events to materialize
OASIS5Common mirage target
ARSON5Crime involving fire
POTUS5Acronym for the head of the United States' executive branch
DNA3Molecular basis of inheritance
AVE3Abbreviation seen on some street signs
NOIR4Film genre

Authors' Notes

OV: I am not a mathematician. I just wanted to make a weird circley diagramless crossword. I had no idea what torus knots were until Herman pointed out that the funny shaped diagram I found online to use in my prototype was one. Learn something new every day I suppose.

In the process of writing this I discovered that the (p,q) notation on the wikipedia page was inconsistent. Of course this was technically explained by an inconspicuous little footnote at the very bottom of the page, but we decided to update the page for clarity anyway. Wikipedia is not exactly a primary source, but we know you will look there anyway.