Lola is really, really excited about looking after the school guinea pig, Bert.

She can't wait because she has learnt completely everything about guinea pigs - 'Bert is just going to just completely love it'.

Lola loves playing with Bert, and she and Charlie even build him his very own guinea-pig run!

But when Bert goes missing, Lola soon discovers that she knows something about Bert that no one else has even thought of...