I suspect Spider's return will be to inform the Street of Emily's death. This could, of course, be done by telephone/letter etc, and there is no house to sell/dispose of, so really, no reason for him to return.
Other than to rekindle his relationship with Toyah who will be on the rebound from Imran.
I suppose he will have other connections in the Street from when he was living there. Kevin, for one, and Rita. Was he around when Dev joined?
Is there anyone else?
Where will he be staying, I wonder? And how long before he's working at the factory - because everyone who ever needs a job ends up either in the factory, or Dev's kebab shop (with a perfectly fitting uniform instantly available)
Ohhhhh, unless he has now trained as a solicitor, and will take over the practice of Adam and Imran 