Lily: The painting!
Marshall: Right, so, um, they told me they threw it in the building's Dumpster.
[flashback to Marshall searching in the Dumpster:]
Marshall: It wasn't in there, but the super told me that he'd seen one Dr. Greer, a veterinarian who works in the building, take the painting out of the trash.
[back:]
Lily: Dr. Greer? Who's Dr. Greer and why did he take my painting?
Marshall: You're about to find out.