To the Illustrious Doctor When and associates from the Trenchwood Institute. We hope you enjoyed our frivolous homage to time travel. As with all of our research in quantum economics, time travel taxation, chrono-scheduling and paradox avoidance, and the Most Lucrative Case Scenario methodology, we feel that this puzzle and our work is of the utmost importance.

Also, I wanted to add that you all looked and smelled just splendid at our presentation. Thank you so much for your time and consideration. You guys are super. Just super. Man o man. Neato

Furthermore, Dr. When/Trenchwood, in the inevitable eventuality of time travel and the subsequential taxation thereof, we promise that Trenchwood will enjoy a dramatically reduce tax rate due to your cooperation and good standing with our Bureau.

And that Bureau is, of course, the Bureau of Asynchronous Time Standardization, Handling, Infrastructure and Taxation. Naturally.

No comment. (I am watching you)

I'm sure that Doctor When would love this, if he had time to spare from his ground-breaking research. I'm not sure he knows that much about movies or TV or books, though. Fortunately,his lab assistants have lots of time for those things. :)

Very good, but Memento/Pulp Fiction group could do with more accepted words for the answer. 'non-linear plot' was the most concise way I could think of to describe it, but it wasn't accepted.

too obscure