Henry Ian Cusick (Desmond on ‘Lost’) joins ‘Macgyver’ cast in Atlanta for season four

The premise: Phoenix Foundation lost its government funding and has been inactive for 18 months.  The team scattered to the winds.

But then dapper actor Henry Ian Cusick, known best for his role as Desmond on "Lost," appears as a billionaire arms dealer Russ Taylor supposedly trying to do good. He finds MacGyver (Marietta's own Lucas Till) and convinces him to help him on a job to prevent a major bio-weapon from going off and potentially killing millions. You know - typical "MacGyver" situation.

Cusick entered “Lost” season two and managed to turn Desmond into one of the show’s most beloved characters. In a way, he’s doing that again with “MacGyver” by entering a show in a major role already in progress.

“I was nervous coming in,” Cusick admitted while shooting his 16th episode late last month. “I didn’t know how I’d fit in. Thankfully, the cast has been so welcoming. The crew has been great. It’s been an easy transition. Although I’m relatively new, I feel very at home.”

In the first episode, MacGyver - bored teaching - quickly gets the Phoenix gang back together even though he has doubts about Taylor’s true motives.

"We were miserable in our new jobs since the Phoenix was gone," said Till during a break in rehearsal at Mailing Avenue StageWorks near Grant Park. He was between takes shooting a mildly comedic concluding scene inside a fake airplane interior with most of the cast.

Till said in many ways, the writers split the characteristics of Eads’ Jack character into two new characters. Tran’s Desi became both the brawn and Till’s love interest. “There was a joke that Jack and I had a bro-mance of sorts,” Till said.

But MacGyver couldn’t smack-talk Desi the way he could Jack. So he does that instead to Cusick’s Russ, who comes across suave and likable but not villainous despite his seedy back story.

Cusick said he is at greater loggerheads with MacGyver's boss Matilda (Meredith Eaton) in part because he's not as organized or focused as she is.

By the end of the fourth season debut episode, which aired last Friday night and featured a little fun with nitrous oxide, everyone was ready to save the world a few more times over. Turner’s massive private cash infusion brought the Phoenix Foundation and its offices back to life. “It’s home,” MacGyver said near the end.

Till, including episodes that haven’t aired yet, has now done 80 episodes in three-plus years and he is grown into the role. Now 29, his still-boyish looks mesh with  more mature demeanor.

“Page count wise, it’s like 40 movies in eight years,” Till said. “When I first started this, I didn’t think I could do this. It was so hard. The memorization was killing me combined with my inability to do anything outside of work.” He said, fortunately, all of that has gotten easier and he has more free time.

And the writers always come up with wackier, crazier stuff for MacGyver to escape, he said.  “This season, we tethered two airplanes together and I go from one to the other to save a kid and his dad,” he said.

“Two days ago,” Till added, “we were on set and all of us got rigged up and got pulled up into a sky. That was a Friday night. We get to fight. It’s been nuts this whole week.”

He also notes that while most episodes the first three seasons focused on peril of the week, this season will be more serialized with the team chasing down a single bad guy over the first 13 episodes.

And Till said the cast is now clicking, minus Eads. “We have settled into this phase where we equally play off each other,” he said.

ON TV

“MacGyver,” 8 p.m. Fridays, CBS