He is joining forces with director Katy Rudd on the show, which will be performed on the set of The Curious Incident of the Dog in the Night-Time, featuring comedy, theatre, music and a live auction, with proceeds split between Ambitious about Autism and The National Autistic Society. 

Olivier Award-winning playwright Simon Stephens and Mark Haddon, the author of the original novel, have written a brand-new detective story especially for the Gala which will feature Treadaway as Christopher Boone, the central character in The Curious Incident of the Dog in the Night-Time. It will be told through a mix of live theatre and video, with filmed performances by Dame Helen Mirren, "Doctor Who" star Matt Smith and "Sherlock" star Andrew Scott. 

The cast of The Curious Incident of the Dog in the Night-Time will be joined by guests that include singer-songwriter and multi-instrumentalist Bat for Lashes, the all-female vocal group The Boxettes and comedian Simon Amstell. Also appearing will be pianist Derek Paravicini who is blind, has autism and severe learning difficulties, and pop singer and songwriter James Christy, who was diagnosed with Asperger syndrome when he was six years old and "discovered" at the age of 14 by his music teacher and now performs all over the U.K. with The James Christy Band.  

In a press statement, Treadaway commented, "Katy and I had the idea to produce an autism fundraising event for when The Curious Incident of the Dog in the Night-Time first started at the Cottesloe Theatre. During rehearsals I’d met Ambitious about Autism's Youth Patron Cian Binchy and he really impressed me and helped me understand what it can be like to live with autism.  We want the money we raise to go towards supporting people with autism and I'm so grateful to everyone who is giving their time and talent to put on the best show possible."

To book tickets, contact the box office on 0844 482 9671 or visit http://www.nimaxtheatres.com/apollo-theatre/a_curious_night_at_the_theatre.