In the first half of a two-part episode, chaos strikes Hope Zion Hospital when a bombing rocks a local charity run. Unsure of the motives behind the attack, the Hope Zion staff can't even take the time to check on their own doctors who were in the race before they all jump in to treat the mass of casualties. With blood supplies running low, Dr. Alex Reid (Erica Durance) and Dr. Jeremy Bishop (Peter Mooney) are given priority to treat a young man suffering from severe injuries. But when it's revealed their patient is the bomber, Alex must battle an angry mob as well as her own conscience to provide the care her patient needs. In the ward, Dr. Maggie Lin (Julia Taylor Ross), still dazed from the blast, jumps in to provide care to Shelby Hart (Genelle Williams), who's pregnant and injured. Tensions rise though when a suspected infection of the mom-to-be leads to the return of Dr. Sydney Katz (Stacey Farber), and the premature delivery of Shelby's baby to save both their lives.