For fast friends the pieces will be works that consist of more than one part. In the way that a friendship consists of more than one person. You could say that the location of a friendship lies somewhere between the friends - so in each of the artworks in fast friends, the 'centre' of the work - if it can be said to have a centre - will be in the relationship between the parts.
Sounds simple, and easy to find works that do that in an interesting way? ... and that will play off each other in the space, and that I like a lot ... well it is enjoyable, but it feels like a constantly changing juggling act with the opening date not far away.
Probably a good idea to spend some time watching the magpie in the back garden: