They're one of the largest wolf packs ever documented, once numbering 37 strong. But when their patriarch and his alpha female are killed by another pack, the Druids' reign over Yellowstone National Park's 30-mile-long Lamar Valley comes to a sudden end - at least for a time. Nature chronicles the turbulent family saga.

Sunday, 2/22/09 from 8-9 p.m. ET
Thursday, 2/26/09 from 4:30-5:30 a.m. ET