They come. They go. And sometimes, they come back: Major actors on major shows that fans grow to love and then are forced to forget.

Soon we will be asked to un-forget Sara Sidle — played by Jorja Fox — the grim, smart, talented member of the “CSI” team who fell in love with Grissom (William Petersen) and out of love with the job.
She’s expected to come back for five or so episodes. Which got us to thinking: Who else has left a major TV show only to return? Here are a few:
Lisa Bonet, “The Cosby Show” — Denise Huxtable was a major member of the Huxtable clan, but left in 1987 to launch “A Different World.” She jumped back to the mother show the following year.
Sherry Stringfield, “ER” — Best known and loved as Dr. Susan Lewis when the show launched in 1994 and became a vital character until she left in 1996. Stringfield was weary of the grind but a long rest ended in 2001, when Dr. Lewis returned.
Ron Howard, “Happy Days” — Richie left in 1980 after graduating from college (then joined the Army) and returned three full seasons later.
Patrick Duffy, “Dallas” — The most famous reappearing act of them all. Bobby Ewing is run down in the 1985 season and returns in a shower at the end of the following. The whole season had been but a dream.