'Agents of S.H.I.E.L.D.' season 4 spoilers: Life Model Decoys to take center stage; EP explains Ghost Rider's departure

After Ghost Rider's (Gabriel Luna) exit, Life Model Decoys (LMDs) will have bigger roles to play when ABC's "Agents of S.H.I.E.L.D." returns for the back half of season 4 next year.

The hit superhero drama brought a popular Marvel comics character to the small screen this season with the introduction of Robbie Reyes, who is also known as the Ghost Rider. He first appeared in the season 4 premiere as a spirit of vengeance, killing gang members on the streets of Los Angeles, and he was a significant character in many of the succeeding episodes. However, his stint abruptly ended when he was seemingly sent back to hell during the midseason finale. In an interview, executive producer Jeffrey Bell explained why the fan-favorite character couldn't make it until the season finale.

"[Ghost Rider is] a lot for 22 [episodes], especially with everything else that we like and care about on the show," he said. "It would feel like one flavor over a long period of time, but we've certainly left it open," Bell added.

Additionally, the producers admitted that "financial considerations" also affected their decision in putting out Ghost Rider's flame. When the series returns on January, the execs can cut down production costs because LMDs are taking center stage, and they won't require much CGI effects compared to Ghost Rider.

According to co-showrunner Jed Whedon, switching gears into the latter part of season 4 is good for the show because it gives the characters more room to grow. S.H.I.E.L.D.'s long-held pattern of trust issues will have a new wrinkle after Agent Melinda May (Ming-Na Wen) was abducted by Dr. Radcliffe's (John Hannah) LMD assistant, Aida (Mallory Jansen), and replaced with an android who looks exactly like her. "We want to not just tell scare stories of things popping out of closets, but the emotional stories — and when you get into trust, that's when things get emotional," Whedon added.

The fourth season of "Agents of S.H.I.E.L.D." returns on Tuesday, Jan. 10, at 10 p.m. ET on ABC.