The Tremendous Baron Time Machine, 4Hardcover, 16 April 2019

W.B. is back and more disappointed than ever when he discovers a new series of popular books that depict the Barons as bumbling fools. His parents M and P, along with Rose Blackwood, laugh at the books until their plummeting reputation starts scaring off the buyers of their inventions, leaving the family without an income.

As family members start disappearing one by one, P realizes that the author of the books is not out to ruin just their reputation, he's determined to erase their past. All of the Barons must race to intercept their rival time-traveler and stop him from erasing the entire Baron family from existence before their time runs out.