Scorpion season 3 episode 4 could feature the return of Mark Collins.Facebook/Scorpion

Tobias M Curtis a.k.a Toby and Happy Quinn are likely to take the centre stage in the upcoming episode of Scorpion season 3. Episode 4 is titled Little Boy Lost and it will be aired on CBS tonight, October 17, at 10pm EST.

Here is the official synopsis for the sequel: Team Scorpion must find a boy from Ralph's class who goes missing on a field trip after he accidentally has a run-in with a deadly criminal. Also, Toby gets closer to finding out the identity of Happy's husband.

Since there are no further details available and the creators are tight-lipped about a new cast member, rumour mills are abuzz over a former member of Team Scorpion. Is it Mark Collins who had a relationship with the mechanical engineer or someone he knows?

Fans will have to wait a little longer mainly because cast member Eddie Kaye Thomas teased in the past that big ramifications will be coming up for Jadyn Wong's character and the behavioural psychiatrist.

However, the shocking revelation about Happy's past would not have a great impact on her relationship with Toby. Executive producer Nick Santora revealed earlier that they will not be struck by lightning that could end their relationship forever. "Eventually, these characters and these relationships are all going to get where they need to be. It's just going to be hard," TV Line quoted him as saying.

In order to find out what lies ahead for Walter O'Brien, Paige Dineen, Sylvester Dodd and Agent Cabe Gallo, watch Scorpion season 3 episode 4, titled Little Boy Lost, live online here. The sequel will also be available online on the official website of CBS.

Meanwhile, the creators have also expressed interest in exploring the past of Team Scorpion. So the followers of CBS series can expect to watch some of the characters' stories in the upcoming episodes.

Check out the official synopsis for Scorpion season 3 episode 5, titled Plight at the Museum, below:

Team Scorpion's simple job at the Los Angeles Natural History Museum turns deadly when they discover thieves robbing a rare gem exhibit in order to get materials needed to enrich a nuclear bomb.