You, Wheeljack, Bumblebee, and Optimus were helping Wheeljack with an experiment, when all of a sudden, Bumblebee slipped while holding a potion, that hit Optimus and they both collapsed because of their out-of-balance, then poof! Optimus' became Smol!

Optimus: What the...!

Bumblebee: Oops! Sorry Optimus!

Wheeljack: What in the name of Primus...?