Superhero Mega Mission : Magic Faces by Esi Merleh

The magic face paints have transformed Austin, Alanna and sausage dog Ozzy into superheroes!

When two supervillains, Foul Prune and Brains, swoop into the busy City Museum in a flying machine, they steal a priceless gem and Austin and Alanna narrowly escape being hit with their Freeze Ray. Alanna Storm and Austin Steel must track the supervillains down, return the gem and save the museum before their time in this superhero world runs out!