A baby--blast! Lord Fredrick Ashton may not feel ready to be a father, but with a little Ashton on the way, he's sure about one thing: The wolfish curse on his family must end soon, before the child is born. Otherwise, he warns Miss Penelope Lumley, a barking baby Ashton is just what we shall have.

Penelope takes on the challenge, for she knows that the fate of her own pupils is strangely bound to the fate of the moon-cursed Ashtons. The missing puzzle piece lies within the fading memory of an ancient mariner named Pudge, a resident of the old sailors' home in Brighton. When Lady Constance's doctor prescribes a seaside holiday, Penelope jumps at the chance to take the three Incorrigible children to Brighton. There, with the help of her friend Simon, she hopes to find out what Pudge knows.

The Ashtons are not the only ones at the beach in January, however. The temperamental Babushkinov family is also taking the winter waters. The Incorrigibles may have been raised by wolves, but the Babushkawoos (as the children call them) are the wildest creatures they've ever seen. Is it more than mere coincidence that these untamed children have turned up in Brighton just as Penelope and the Incorrigibles arrive?