Cook, who left the CBS series in September after being dropped for "creative reasons," will appear in the Season 6 finale on May 18, Deadline reports. She'll rejoin the show full time in the fall.
The procedural has undergone numerous changes this season. In addition to Cook's unexpected departure, Paget Brewster was demoted before deciding to leave. She has an option to return as a regular next year, but has recently joined the NBC pilot My Life as an Experiment. Rachel Nichols came on in December to fill the void. Original castmembers Thomas Gibson and Shemar Moore have yet to renew their contracts.
Earlier this week, showrunner Edward Allan Bernero announced to the cast that he was leaving the series. Longtime executive producer Erica Messer will take over.
Are you excited for the return of JJ?