Conversation so far:
What happened in 1915?
Jerome Kern introduced him to the writer Guy Bolton, who became Wodehouse's closest friend and a regular collaborator.
what did the two collaborate on?
This was Miss Springtime (1916), which ran for 227 performances--a good run by the standards of the day.

Question: what did they do next?
Self-contained rewrite: what did P.G. Wodehouse and Guy Bolton do next after Miss Springtime?