Richie Millstone, Evil Daryl & the Dragon Planet

Richie Millstone, Evil Daryl & the Dragon Planet is the fourth book in a ten-book series about the adventures of a teen boy and his friends as they travel through time on a machine built by the teen's father. They meet tons of new people along the way and help those that need it. The fifth book in the series will be the final book where the kids are teens. The sixth thru tenth books will be more on the kids' lives as they grow into young-adults thru their older years.