Costume

As one of the effects of Autism is having sleep issues, insomnia and waking up in the middle of night to carry out tasks, our thriller is set at 3AM, so he'll be wearing pyjamas. To corroborate with the idea of the boy being obssessed with planes, we've decided that he'll be wearing pyjamas with cartoon planes on them. This will reinforce his obssession and also make him seem more childlike.

Here is an example of similar pyjamas.