Sarah Hagan

Alex treats a patient whose religious beliefs place her life in jeopardy. Meredith wants to know more about Derek, and Izzie ponders contacting her estranged mother.

The wife of a Marine, who specialised in K-9 bomb detection, urges the NCIS team to investigate the recent death of her husband in Afghanistan.

Naomi seeks Fife's help with William's experimental treatment for ALS; Violet and Amelia treat a woman with a brain tumour; Sheldon goes after Charlotte's affections.

Wielding a mystical new weapon, Buffy rejoins the fray on the eve of the final confrontation with Caleb.

Faith returns to Sunnydale just in time to meet The First's evil agent, Caleb. Buffy leads the troops into a battle with Caleb, which ends with two dead Potentials and a seriously wounded Xander.

After their horrifying loss at the vineyard, the gang turn against Buffy and begin to follow Faith instead. Meanwhile, Spike and Andrew travel to an old church to question a priest about Caleb.