As Monk has a fear of flying, he takes Dioxynl, a drug that relieves him of his compulsions and phobias, but limits his ability to solve crimes.

Examining the scene, Monk finds that the fatal shot was actually fired from the adjacent apartment, with a painting moved to cover the hole in the wall.

A bullet hole in the couch, attributed by the police to a test shot, was fired to get gunshot residue on Vigg's hands and make the death look like a suicide.

Stoffmacher thinks Leupolz fled after accidentally killing Vigg, but Monk suspects both Leupolz and Vigg were killed by a third party, noting ashes from burned papers in the fireplace and a missing pillow which he thinks was used as a silencer due to the feathers scattered through the apartment.

This makes him and Natalie think that Kroger is part of a massive conspiracy to prevent Monk from ever re-joining the police department.

The conspiracy theory is strengthened when Captain Stottlemeyer and Lieutenant Disher research Rahner and find that he was in the Bay Area two weeks before Trudy's death, on a lecture tour funded by Monk's old enemy, Dale "The Whale" Biederbeck.

Stoffmacher argues the evidence for this theory is insufficient, so Monk and Natalie fly to Berlin and question Leupolz's editor in hopes of confirming a motive.

Monk takes Dioxynl to enable him to fly back to Lohr and search for the place where Rahner hid Leupolz's body until morning.