Each clue in the first set clues the name of a puzzle from a previous Mystery Hunt that involved a crossword with an entry at 56 Across. (Other such entries from past puzzles are MAE, HAS, and AMIGOS.)
Each clue in the second set clues a (usually fanciful) term that is one of those 56 Across entries with a letter added at the start and end; these terms are in alphabetical order. Matching these up we have (in the first-set order):
| Column 1 clue | Clued puzzle name | Year | 56 Across entry | Column 2 clue | Clued phrase | Added letters |
|---|---|---|---|---|---|---|
| Singing or hosting talk shows, for Dinah (1 5 5) | A Shore Thing | 2000 | NERO | An individual instance of decay (3 3) | ONE ROT | OT |
| What toroidal stockings keep doing (7 2 7) [The earlier one.] | Running in Circles [specifically, the earlier of the two puzzles with this name] | 2004 | SNN | Fig. shown on a portal from Gates's co. (3 2.) | MSN NO. | MO |
| Drunk on a wheelless conveyance (14) | Sledgehammered | 2014 | SCREAM AT | Where RingCentral Coliseum visitors use a card to get dairy products (1'1 5 3) | A'S CREAM ATM | AM |
| Lone instance of St. Thomas scoring in rugby (3 4 3) | One More Try | 2011 | ERO | Equip with another marsupial (5) | REROO | RO |
| GAVE FIZZY AX WEIGHTS, say (... 5 3 4 6 6) | ... fixes the wavy zigzag jumble | 2013 | THE | "And the thocht baith brings the licht to my e'e." (1' 4) | O' THEM | OM |
| Financial instrument signed "Carolyn Gold Heilbrun" (5-5) | Cross-Check | 2000 | ABLE | Garland as awesome as the Beatles (3 3) | FAB LEI | FI |
| That whip with a little flammable cord sticking out (3 6 5) | The Wicked Switch | 2012 | ZEN | Robert Graves sequel set over 43 decades later (1, 4) | I, ZENO | IO |
| Occasions when ἀνθρώπω occurs as ἄνθρωπος, say (4 13) | Dual Singularities | 2009 | ORE | Jovian who umps over the moon? (2 3) | IO REF | IF |
| The theory of functions important to android operation (4 8) | Data Analysis | 2006 | SOL | Sicilia, per esempio (5) | ISOLA | IA |
| Term uttered by someone smoothing concrete angrily (8 9) | Floating Crossword | 2015 | TAN | Reeked (5) | STANK | SK |
| You cannot spell "ill" as "il" or "ll" (3 3 2 5 3'1 3) | Two Out of Three Ain't Bad | 2007 | TENOR | Egyptian sphere representing the solar disc (4 3) | ATEN ORB | AB |
| Collection of insults (8) | Disarray | 2006 | EAST | The Undiscovered Banquet (5 1) | FEAST X | FX |
| Encyclopedia layout that leaves no room for "Crooning" (6 7 14) | Crimes Against Cruciverbalism | 2016 | LEDA | Lentils flavored with top-fermented malt (3 3) | ALE DAL | AL |
| Would you like some Roman spelt from Rebec in "Planet of the Daleks"? (3 3?) | How Far? | 2016 | ACLU | Icky-poo affection for an Apple computer (3 3) | MAC LUV | MV |
| Figure seen twice above (2) | 14 | 1994 | WANT IN | Portmanteauish gin or vodka cocktail invented by Rheon of Misfits (8) | IWANTINI | II |
| Things a stooge finds cozy about the underworld (8 11) | Creature Discomforts | 2007 | EDINA | Was the best at HAL-like tech (3 2 2) | LED IN AI | LI |
| Occurrences when actress/writer Mary Kay makes Jell-O (5 8) | Place Settings | 2019 | ALUMS | Putting hundreds of transistors on chips between Korea and China (4 3) | YALU MSI | YI |
The added letters at the start and end spell out two clues employing Roman numerals:
| Clue | Answer | Explanation |
|---|---|---|
| OMAR OF II IS A FAMILY | SY | Omar Sy was in the movie Two is a Family. |
| TOMOMI OF AKBXLVIII | ITANO | Tomomi Itano was in the band AKB48. |
The "specific location" is 56 Across, which in old Italy (that is, in Roman numerals) would be LVI ACROSS.
Removing the "heart" (middle letter) and separating these two people with it gives:
SY + LVIA[ ]ROSS + ITANO
so the answer is SYLVIA ROSSITANO.