Note: This is another in my sequence of post-Mystery-Hunt cryptics, which started with "Still There," "Post-Game Predictions," "The Sequel," "Power Lines," "A Lesson in Cryptography," "Yet More Villainy," "Further Escapades," "Time X*X," "Honeymoon in Segas," "If At First You Succeed," "Another One From The Vault," "Next Winter: Wonderland," "DAB," "Some Extraction on the Side," "Another Campaign," "Mind The Sharp Bits!", "Through The Wood", "Newbie Toonie", "Tomezone", "Museum Pieces", and "Nethermore"; this one was written before the 2026 hunt and refers to the 2025 hunt. "NI3," as is usual in the National Puzzlers' League, indicates Merriam-Webster's Third New International Dictionary.

After the Shadow Diamond case, you opened your own detective agency, and always know what's happening in MITropolis; now certain things that aren't happening have aroused your suspicions. Specifically:

1. Suspicious inactivity. At night, Rover goes around barking to intimidate six locals (who just want to leave), and Katrina goes to Richard & Oscar's Pub to sing songs round the piano (and down a fifth). Six answers can be altered before entry to reflect the former, and seven the latter — but in each set, one answer will be entered unaltered, because Rover and Katrina have been sneaking out occasionally to do something else. Order Rover's six (pre-alteration) answers alphabetically, and Katrina's seven by the usual ordering on their unusually spelled key parts. If the mth answer on Rover's ordered list is the one entered unaltered, take the mth letter of every Rover clue in that same order; then do the same, replacing "Rover" with "Katrina" and "mth" with "nth-from-last." These two sets of letters will name the two ringleaders (call them A and B) of this new caper.

2. Ringleaders. Reflecting A, who pulls strings to see what develops, nine answers can each be altered by pulling one letter out, and then adding one letter (not necessarily different) in the same place and then in two more places farther to the left. Reflecting B, who has the final say remotely by phone, eight answers can each be altered by replacing βγ with α for some letter triple αβγ on a 1930s telephone dial. As in 1, though, one answer in each set will be entered unaltered. Order A's clues by the chain of letter replacements (which indicates what A is pulling) and B's in dial order, and redo the next-to-last sentence of 1 with "Rover," "m," "Katrina," and "n" replaced by "A," "p," "B," and "q," to get a four-word phrase. (Note: Each of 1 and 2's thirty clues contains a noncryptic clue for its altered answer, whether entered or not; these thirty altered answers include six proper names, two hyphenated terms, one unabbreviated phrase, and three initialisms of various kinds.)

3. Clue trail. The wordplay in each of the other twenty-nine clues yields a letter string in which one letter is replaced by an abbreviated compass direction; use 2's final phrase to obtain a number x from that clue, and draw a straight line in the grid starting at that letter and traveling in that direction for x squares. Then (a) fourteen lines will end at the start of another line, (b) fourteen will end elsewhere in the grid, and (c) one will end outside the grid. The chain of replaced letters from the (a) and (c) lines will say where the caper from 1 and 2 will take place; in clue order, using m and n from 1, read all the (b) clues' mth letters to see what this caper consists of, and all their nth-from-last letters to see the evidence that would remain afterwards … except that:

4. Nothing to see here. A cover-up has been arranged by the team's fifth member, a non-MITropolitan femme fatale who is an old hand at cunning nighttime plans; her (apt-sounding) name is one of the (b) answers. In clue order, starting at her (b) clue and looping around to the beginning, read (separately) the (b) clues' mth letters, pth letters, qth-from-last letters, and nth-from-last letters (using m and n from 1 and p and q from 2) to see what will hide the evidence from 3. If that seems mathematically impossible, alter the middle word of the caper location by undoing all four unused answer alterations (first the two from 1, then the two from 2) to see the location's former name, which makes it possible. Finally, for each (b) line, copy the letter at its end to the position just outside the grid where that line would reach if extended; counterclockwise around the grid, starting where the (c) line ends, these will say what about the location makes it possible (and also say who can help uncover the truth).

ACROSS

DOWN

1. Key software on a computer has old port that was a bad idea
2. Produce overexcited howl for chemist Alfred
3. Tailors and hinds, for instance, flow into the heart of Nassau
4. Niceishly maintains seafaring life
5. Nurtures until (say) harvest season ends
6. Get some liquid from area taken away from Oz city
7. A tome misquoted part of a love note from Dalí or Goya (2 wds.)
8. Fry tried to find premiere of act on the radio
9. Launched meat zine secondarily presenting dorado cut in twain?
10. Moisture covers a Tennessee horseman
12. At Aswan, shaved with Gillette razor
17. Cutesy, somersaulting robosheeps?
18. Freedrifting, bareclawed Sisera's destroyer
19. Overseeress'd internally see "larghissississimo"?
21. Of eye parts that might be blue as a chunk of underdone meat
23. For example, coveting tritium waste generated by drying machines
25. Phony weight that rises upwards
26. Extensive vehicular journey
27. Just "sonless" (lacking sons)
28. A (huzzah!) rat that's tossed at an early netizen? (abbr.)
32. "Look incongruous" chiefly connotes "get all soapy"
34. Leave snugger electrified port in Asia with South American shrub
35. Bush's city's boring and ridiculous
37. Informally marries less naughty Montagnes in France
38. Kmart competitor's blights
40. Little fruit that Swiss mister in back rapidly pitted
42. Roland will omit the fourth and sixth character
43. Hires large basketball players from Brooklyn
44. Deputy in front, protecting old New York movie house
45. Signore Chaney — then, at last, Lloyd