Final answer:
Without specific context or reference to a work, it's not possible to determine if Nick plays the role of Tom's keeper, Jordan's attendant, or Daisy's lookout during the party.
Step-by-step explanation:
The role that Nick plays during the party attended by the main characters isn't explicitly mentioned in the question, but based on typical scenarios within novels and plays, it's possible to infer that characters often serve specific roles at social gatherings. However, without context from a specific text or excerpt, it's challenging to ascertain whether Nick is Tom's keeper, Jordan's attendant, or Daisy's lookout. Each role would suggest a different type of responsibility and interaction with the other characters present. Without additional information or a clear reference to a work like F. Scott Fitzgerald's The Great Gatsby, where Nick Carraway is a central character, the answer remains undetermined. Nonetheless, in literature, characters in social settings often undertake defined roles that contribute to the plot and their relationships with other characters.