From the New York Times bestselling author of the Sisters Grimm and NERDS comes the second book in an action-packed middle grade series with equal parts humor and heart!

When Finn is saved from the Time Rangers by an older version of himself, it comes with a catch. Old Man Finn needs Finn and his friends, Lincoln and Julep, to help him win battles he lost years ago against the Paradox, a terrible creatures obsessed with revenge against Finn's father. If they succeed, he promises to tell Finn where his father is. He even gives them a pair of time-traveling pajamas to help them with their quest.

There's only one problem. The pajamas malfunction almost immediately. Along the way the kids avoid being eaten by sabretooths, shot by revolutionary war soldiers, and start a war with a town full of holograms, all in an effort to fix the jammies.

Just when their goal is in sight, Julep gets sick. Only...it doesn't seem like she's sick. It seems like she's changing. The adventure may cost Finn more than an old pair of pajamas--it may cost him his friends!
Praise for The Finniverse: 

Amazingly fun…fans will beg for the next volume. A must-buy for middle grade sci-fi fans.”—SLJ

"Buckley (the Sisters Grimm series) spans the galaxy with this humorous story…. An action-packed romp."—Publishers Weekly

“Hold onto your butts as Buckley, author of the popular Sisters Grimm and NERDS series, throws his newest adventure into hyperdrive from page one . . . . Light-speed fun.”—Booklist

“Realistic kids, wild aliens, and unicorns sure to surprise readers add to the fun . . . if the laughs don't keep the pages turning, the action will.”—Kirkus Reviews

"Perfect for Max Brallier and Doctor Who fans seeking an action-packed sci-fi adventure."School Library Journal 

"A satisfying planetary romp, and the promised sequel will no doubt have a crew of fans."The Bulletin 

"Funny and fast-paced."—The Week Junior US