“Fruit of the Vine” centers around two sisters, MANDY and STEPH, operating a struggling winery in Napa County, California called Twin Bicycles.

Mandy, a graduate of UC Davis’ viticulture program, is up to her earlobes in credit card debt and spends her weekends with spreadsheets to keep afloat the winery—which only exists because the sisters’ late grandfather (a failed grower himself, but later a successful engineer) invested heavily in Twin Bicycles initially. The ashes of the grandfather now occupy a bottle stashed on a shelf in Twin Bicycles’ office, a run-down, single-room construction trailer.

Steph, who received her MBA from Stanford, attempts to enjoy what little life she has when she isn’t driving around the state in a constant attempt to get Twin Bicycles on as many grocery store shelves as possible. She resents the fact that Mandy looks down on her social life and often calls her sister out for having a martyr complex.

According to the sisters’ original business agreement, Steph owns all the vines and land, while Mandy owns all the intellectual property of Twin Bicycles.

In Act I, Steph introduces the idea of bringing in ANGELO to help the pair finance the business and gut competitors. Angelo is well-known for his strategy of buying up failing vineyards and labels for his cheap but extremely popular brand Peter Maes. Mandy, believing Angelo to be predatory, is incensed Steph would invite him for a meeting.

During the meeting in Act II, Mandy and Angelo wrestle. Mandy leaves after winning the tussle, disgusted by Angelo’s chauvinism and Steph’s attempts to placate him. While she is out of the office, Angelo tells Steph to buy Mandy out of the business if she wants to find real success—and that he would provide Steph the capital to do so. When Mandy re-enters, Angelo tells her that he has no interest in the winery, claiming it is a lost cause.

Act III finds the sisters in crisis mode. Before Steph can really consider Angelo’s offer, a fire destroys the vineyard. With the vines ruined, Twin Bicycle’s only asset is the label, which belongs to Mandy according to the sisters' original agreement. Mandy convinces Steph to look for jobs in Silicon Valley, a move Steph concedes is what she has actually always wanted to do. After Steph leaves to pack, Mandy takes a meeting with Angelo. He accuses Mandy of starting the fire, an accusation she vehemently denies. Regardless, he agrees to buy the label and offers Mandy a job, a proposition she considers as the curtain falls.