I saw the entire episode when it aired last week. What follows is from memory.
CAUTION: POTENTIAL SPOILER ALERT - Scenes involving absinthe are in green
Early in the episode, Bob is with his family to by a turkey from the supermarket. He's seen speaking with the store turkeys and Bob mimics the turkey's speaking back. This lets the viewer know that Bob is a bit intense about Thanksgiving.
His landlord, Mr. Fishodor, Makes Bob an offer; borrow Bob's family for an evening in exchange for five months free rent on the restaurant, all to impress and entice an old flame to sleep with him.
Mr. Fishodor lives in a Victorian mansion that seems to be stuck in time at around 1900.
While the members of Bob's family are practicing their roles as the family Fishodor, Bob is preparing the Thanksgiving dinner.
While Bob is preparing the turkey, he sees the bottle of absinthe and initially ponders, "hey, what's this?". He verbalizes a recollection that he had heard absinthe made you hallucinate. He takes a swig (straight) and within seconds, starts seeing items around him melting.
As the evening wears on, he drinks more and becomes more drunk. After he puts the turkey in the oven and sets the timer, he falls asleep on the floor next to the stove and begins to have a hallucinogenic influenced dream. Upon his waking, he's still very drunk and behaves a bit like that uncle every family has that drinks too much at parties; loud and obnoxious. Bob bursts into the dining room with the roasted turkey, he insists on giving his, "traditional Thanksgiving toast". Some back-and-forth between Bob, his wife & kids, and Mr. Fishodor, result in Bob kidnapping the turkey and running off down the hall. This puts a crimp in Mr. Fishodor's plans and Mr. Fishodor's female guest, who by the way is a crack shot, goes "hunting" after Bob and the turkey, which has become a metaphor for Bob. While Bob is being chased through the mansion, he is speaking to the turkey and mimics the voice of the turkey as it speaks back to him. The scene climaxes in Bob running into a room, closing the door, and the female guest firing a shot through the door followed by a thud that sounds like a body collapsing on the floor.
Bob's family rush to the door to find Bob lying on the floor and exclaim, "DAD!". This initially stimulates the female guest which is relayed to Mr. Fishodor as amorous gestures. Bob comes around and it's revealed that it was the turkey that took the bullet. Bob goes through a death-scene with the turkey voicing the turkey's last words. It's further revealed that this was an elaborate plan to get Mr. Fishodor laid. The guest declares that she has too much respect to not be with a man who's not in a miserable loveless marriage and leaves.
Bob and his family eventually get back home and have their Thanksgiving dinner with the salvaged turkey.
He ends up ruining the dinner