This is a blind guess but is Detop1 “The Fifth Element”?
Let me restate NDP 25 again:
NDP 25 - As a detective recuperating from a mental breakdown triggered by a traumatic case listens to a Mozart composition, his occasional girlfriend tells of the piece’s therapeutic effect.
That was my first thought, because it does take place on the third floor (IIRC), but Harry is not a man, and the thing was not a giant (an ogre?). Maybe they worded it incorrectly.
I’m bored at work, so here’s a couple:
L4L-11 An evil man who lives on an island uses thumbs to hurt people.
L4L-12 A detective chastises a co-worker on his choice of condiments.
Oops, too late.
L4L - 14 A man mistakes an exterminator’s vehicle for a police car.
L4L - 15 A man sleeps under his couch.
L4L - 16 The only survivors were a baby and an alcoholic.