STEM Saturday. Science play and learning from 10 a.m. to 1 p.m. at Homewood Science Center, 18022 Dixie Highway.

Young Writer’s Club. Meet from noon to 1 p.m. in the multipurpose room at Homewood Public Library, 17917 Dixie Highway. Register here.

Off-leash Ride. A leisurely just-riding-around nine-mile ride every Saturday. Route includes Butterfield Creek bike path, Rovers Run and Izaak Walton Preserve. Starts at GoodSpeed Cycles, 2125 183rd St., at 8:30 a.m. sharp, ends back at the shop 9:45ish for donuts.

Chicago Knockouts Roller Derby. Wreck League bout will start at 8 p.m. Doors of the Homewood Auditorium, 2010 Chestnut Road, will open at 7:15 p.m. Tickets are $15 online, $20 at the door. Trackside tickets are $20, front row $25. Accessible seating available at no extra charge. Tickets are available at chicagoknockouts.com.