A moose, a goose, and a mouse ride a loose caboose to find the perfect house in Moose, Goose, and Mouse, a picture book written by the late Mordicai Gerstein and illustrated by Gerstein and Jeff Mack. Released this month by Holiday House, the book has a bittersweet back story involving the collaborators’ chance meeting, a fast friendship between two kindred spirits, an unexpected working partnership, and a rewarding cap to a distinguished career for Gerstein, winner of the 2004 Caldecott Medal for The Man Who Walked Between the Towers, who died in September 2019.

Gerstein and Mack initially crossed paths at an event in Northampton, Mass., in 2009, the year after Mack had published his first solo work, Hush Little Polar Bear, with Roaring Brook’s Neal Porter Books. “I’d never met Mordicai, but I knew of him, and knew that he had been published by Roaring Brook,” Mack recalled. “I went up to him and said, ‘I think we might have the same editor—mine is Neal Porter.’ And he looked at me and said, ‘Oh, mine is Simon Boughton.’ That was the end of the conversation.”

Fortunately, it was not their last exchange. Not long after that encounter, Gerstein emailed Mack saying he was looking for a new writers’ group on their shared western Massachusetts home turf and asked if he knew of any. “I told him I had been part of a group for a few years, and invited him to join us,” Mack said. “He did, and there was an instant chemistry among us.”

Some five years after Gerstein became a member of the writers’ group, Mack added, “It became clear to Mordicai and me that we had many similar tastes—we liked the same music, artists, and books, as well as traveling and food, so we started getting together for lunch and for trips to MASS MoCA for concerts and art exhibits. We became close friends.” Sharing an especially fond memory, Mack noted, “At the end of our last drive together, he turned to me and said, ‘You know what? We sure can talk.’ He was so right.”

An Unexpected Closing Act

For executive editor Grace Maccarone, who first worked with Gerstein on The Sleeping Gypsy (Holiday House, 2016), learning that the author wanted to tackle a new book came as a happy surprise. She had most recently edited Gerstein’s 2019 graphic novel, I Am Hermes! “There are about 250 illustrations in that book,” she explained. “Mordicai worked on it for a long time, and it took a lot out of him. When he brought the final art into the office, we spread it out for everyone to see and there was quite the celebration. He was very proud of it, but he told me that it was probably his last book.”

When Gerstein had a change of heart and approached Maccarone about doing a new book—one less extensive than Hermes—she suggested he try a light story, perhaps one in the publisher’s I Like to Read format. Instead he proposed Moose, Maccarone said, “and I was thrilled. It’s a joyful romp with wonderful characters. The story really is about going on a journey with friends and ending up at a better place. There was a deep spiritual side to Mordicai, and I always wondered if he was thinking about his own journey to a special place as he created the book.”

After Gerstein decided that he was interested in illustrating Moose in collage style—a first for him—he reached out to Mack for guidance. “Mordicai remembered my collage art in The Things I Can Do,” Mack explained, “and he said, ‘Would you be willing to show me some of the digital tricks you did to make those collages work?’ ” Mack said he went over to Gerstein’s studio and scanned some sample abstract drawings he had made, and used the computer to collage them. “Mordicai had experimented on the computer before, but this was the first time he dove in head-first, making all of the art for a book digitally. We played around and got the technique down, and after a few follow-up phone calls, when I talked him through the process again, he figured it out.”

In a subsequent phone conversation, Gerstein (who had successfully battled cancer in the past, but it had returned) shared some somber news. The author told him that he was not feeling well, and asked Mack if he would help him complete the art for Moose. “He also wondered if I would be willing to finish the book if he was not able to do any more work on it,” Mack said.

All Hands and Hearts In

Mack agreed, and Gerstein brought his sketches and drawings to Mack’s studio and the two scanned them into his computer. “As time went by, I would bring my laptop to Mordicai’s house and sit at his bedside,” Mack said. “We’d make adjustments here and there in the color, and he’d email me with his feedback. And when had got through half of the book, he told me, ‘OK, you’re on your own.’ ” Gerstein passed away several weeks later.

Back when Gerstein had told Maccarone that he was not able to finish the book, but she need not worry since Mack was going to complete it, she sensed that Moose was in good hands, “Mordicai told me that Jeff knew exactly where to take the book, and he was right,” she said. “Jeff’s finished art was exactly what I expected. He had worked so closely with Mordicai that he was able to execute his wishes seamlessly. The book is totally Mordicai’s vision and he would have loved it. He really trusted Jeff—they had a lovely friendship.”

Grateful for the Holiday House team’s support after he took over the reins of Moose, Mack noted, “Grace deserves a lot of credit for facilitating the process and making the book happen. It was a labor of love for us all, and for me, getting to know Mordicai even better and being able to help him out with his last book was an important, meaningful thing in my life. I am honored that he had faith in me and trusted my judgment to finish his work. I think he’d be really happy with his final book—it so perfectly represents his playful personality.”

Mack observed that Gerstein’s tackling of a new art medium at the end of his life was entirely in character. “Mordicai believed in trying everything out to see what he liked—in all aspects of his life,” he said. “The last time we went to MASS MoCA, we were in the gift shop, and I turned around to find him with a furry blue monster mask on. So, I picked up a pink one and we posed for a photo. I’m sorry to say that this is the only picture I have of the two of us together—I’d love to have one showing our faces. He was a creative, intelligent adult with a willingness to be a kid, which is something I will always remember.”

Moose, Goose, and Mouse by Mordicai Gerstein, illus. by Gerstein and Jeff Mack. Holiday House, $18.99 Jan. ISBN 978-0-8234-4760-2