Dennings continued working on television, guest-starring on "Without a Trace" as a teen whose boyfriend goes missing, and on "Less than Perfect" in 2003. In February 2004, she was cast in a pilot for CBS titled "Sudbury", about a family of modern-day witches, based on the 1998 film "Practical Magic", but the series was not picked up. Dennings had a recurring role on "ER" from 2005 to 2006 as Zoe Butler, and guest-starred in the CSI franchise twice: first on CSI itself, as Missy Wilson, in the 2004 episode "Early Rollout". Then, on "" as Sarah Endecott, in the 2005 episode "Manhattan Manhunt".