A new Doctor Who show wants to hear from young fans of the Time Lord.
The CBBC show will be called Totally Doctor Who - and they want keen kids to get involved.
There's the chance to be one of eight cadets undertaking the Companion Academy challenges, with the winner getting a day on the Dr Who set.
Brainboxes can try Who-ru and win serious prizes if their questions stump studio guests or you can simply send in your queries for the cast or crew.
If you want to try the quiz, Who-ru, send in your three best Doctor Who facts (about the ninth and tenth Time Lord).
If you want to enter for Companion Academy, send a video of yourself, no more than a minute long, explaining why you'd make a great cadet.
Previous time-travel experience isn't essential, but you must be between seven and 12.
If you're sending a video, make sure your parent or guardian gives their permission in a letter. Send it in along with your tape.
The address is: Totally Doctor Who, PO Box 5158, CF5 9BD, marking whether it's a Companion Academy or Who-ru entry, or find out more information using the link on the right hand side.