Wil Wheaton, a frequently tweeting actor best known for his role as Ensign Crusher on "Star Trek: The Next Generation," will return to "Eureka" in a seven-episode arc to air in the second half of the Syfy series' fourth season.
Wheaton turned up earlier this season in the form of Dr. Isaac Parrish, a headstrong scientist.
When season four continues on July 18, he'll butt heads with Dr. Douglas Fargo (series regular Neil Grayston) for the attention of Day's new character, a quirky Department of Defense visitor to the strange titular town.
Lee will make a cameo in the summer premiere as an expert on gamma rays. Hulk smash if there's no reference to Hulk!