When the daughter of two blacklisted Hollywood writers meets the son of a mysterious apothecary in Cold War London, be prepared for anything:
A truth serum
An invisibility potion
the ability to transform into something else
A Chinese scientist
and............ maybe the chance to save the world!
There was a turtle by the name of Bert
and Bert the turtle was very alert;
when danger threatened him he never got hurt
he knew just what to do...
He'd duck! [gasp]
And cover! (male) He did what we all must learn to do
(male) You (female) And you (male) And you (deeper male) And you!'
[bang, gasp] Duck, and cover!'