If you're going along to watch The 39 Steps next month, you may wish to take along some historical fancy dress.

The play at the Criterion Theatre celebrates its fourth birthday on September 9th 2010 and is to host a vintage tea party to commemorate it.

You'll be able to sample cream cakes and tea-based cocktails in your spy-like fancy dress costumes, as well as watching the comical thriller in all your finery, according to Broadway World.

This could be the perfect event for people who like murder mystery nights, as it offers all the dressing-up opportunities while letting actors do all the work for the story!

Given the retro nature of The 39 Steps, you could consider a gangster fancy dress costume.

The play tells the tale of a man called Richard, who goes on the run after being accused of a murder and finds himself mixed-up in international espionage.