Nate the Great hates mushy stuff. But when he spies a big red paper heart taped to the outside of Sludge's doghouse, Nate knows he must help out his favorite pooch. Wh has left Sludge a secret valentine? It's a mystery until Nate finds out his friend Annie is missing a valentine. The case seems easy. Nate is relieved. No more mushy stuff. That's what he thinks.

Marjorie Weinman Sharmat has written more than 130 books for children and young adults, as well as movie and TV novelizations. Her books have been translated into nineteen languages. The award-winning Nate the Great series, hailed in Booklist as "groundbreaking," has resulted in Nate's real-world appearances in a New York Times crossword puzzle, sporting a milk mustache in magazines and posters, and on more than 28 million boxes of Cheerios. Marjorie Weinman Sharmat and her husband, Mitchell Sharmat, have also coauthored many books, including titles in both the Nate the Great and the Olivia Sharp series. The Sharmats live in Tucson, Arizona. Marc Simont won the Caldecott medal for his artwork in A Tree Is Nice by Janice May Udry, as well as a Caldecott Honor for his own book, The Stray Dog. He illustrated the first twenty books in the Nate the Great series. Marc Simont lives in West Cornwall, Connecticut.