When Lily starts to worry that she and Matt Furnish might be incompatible, Jas suggests adapting the plant species comparison software they are using in class to assess the compatibility of humans. She calls this the Love Machine. Martha warns Jas that this might spell heartache and disaster, but Jas shouts her down - it's a love predictor, what good can't come of it?

Lily is initially delighted when she and Matt score 97% compatibility, but immediately starts to obsess over the 3% incompatibility, whilst Martha is horrified to discover her most compatible mate is apparently Ollie!

Focussing on the little things she doesn't like about Matt means Lily's able for the first time to be cool around him - that is until she starts to find those little things adorable, too! She's soon back to square one and feeling awkward in his presence.

Martha and Ollie are delighted when they finally realise that there are different types of compatibility and their 100% score doesn't mean they have to be a romantic couple.

When the Love Machine predicts that her dad is compatible with head teacher Mrs Griggs, Jas is horrified, especially when it seems that her dad and Mrs Griggs are keen on each other!