Lord Fredrick Ashton may not feel ready to be a father, but with a bouncing baby Ashton on the way, he's sure about one thing: The wolfish curse on his family must end soon, before the child is born, "or a Barking Baby Ashton is what we'll get," he warns the household's governess, Miss Penelope Lumley, who willingly takes on the challenge. When Lady Constance's doctor prescribes a wintry seaside holiday to strengthen her constitution, Penelope jumps at the chance to take the three Incorrigible children to Brighton. Once there, she hopes to persuade the old sailor Pudge to reveal what he knows about the Ashton curse.

But the Ashtons are not the only ones at the beach in January. The passionately temperamental Babushkinov family is also taking the winter waters. The Incorrigible children may have been raised by wolves, but the Babushkinov children 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?