The small silences in this episode are rich and absorptive. They’re too much, though, for Hannah, who keeps breaking them to muse about the artifice of it all. When her friend Marnie (Allison Williams) enters one apartment, newly single and almost radioactively aglow, she doubles the obliviousness. It’s unclear she even knows she’s at a play.

They’re there to see Adam perform as half of a squabbling married couple, but by the time the play reaches its grisly climax, none of these people are really paying attention. Adam looked across the courtyard at Jessa, who’s vamping at him on a fire escape, while Hannah watches them both in disbelief. They ignore the screams and barely notice the amateurish plaster statues that stand in for the victim and her killer. There’s just Brenda Lee misting up the soundtrack.

Basically, a re-enacted crime loses out to a figurative one. It’s one of the show’s most sophisticated and most intricately filmed gags about selfishness. The camera glides toward windows. It cranes downs at the plaster stand-ins. It oscillates from Jessa to Adam to Hannah. Perhaps you think about “Rear Window,” “Monsieur Hire,” “Stakeout” or any other movie involving voyeurism, danger and a little melodrama. And the atmosphere is so rich you can practically feel the balm of warm spring air. But Hannah and Marnie peel off to commiserate. And by the time you see these two spread out on somebody’s bed, they’ve cast themselves in their own sitcom: “The Sorrow and the Self-Pity.”

But the show manages to maintain the gravity of both transgressions: an ambitious if seemingly dumb take on real tragedy and the tragedy that Hannah thinks is her life. It’s a kicky, poignant half-hour of television — half of which is spent elsewhere at a Manhattan party, featuring Hannah’s roommate, Elijah (Andrew Rannells), who is trying to hold his own among greasy gay celebrities. Each plot warranted its own episode, but that was “Girls” this year: so many good ideas, so little space to unfurl them.

There were moments during the series’ underrated fourth season when, between Hannah’s damningly indulgent stint at the Iowa Writers’ Workshop and the invention of a carnivorous art-monster named Mimi-Rose (Gillian Jacobs), the show looked as if it had found its groove as a creative-class farce. This fifth season ended on a not-dissimilar note, after Hannah runs into Tally (Jenny Slate), a college classmate, with a dark cloud of hair, who has become a literary star. She’s like Bizzaro Hannah: Her narcissism doesn’t repel success; it vacuums it up.