Sherlock Holmes (Jonny Lee Miller) and Joan Watson’s (Lucy Liu) knowledge about space will be put to test in Season 5, episode 4 of “Elementary.”

According to the synopsis for the episode, titled “Henny Penny The Sky Is Falling,” the crime-solving duo will find themselves drawn into the world of asteroid research while consulting on the investigation of a financial analyst’s murder.

Since it appears that Sherlock and Joan are not adept in astronomy, executive producer Rob Doherty told TVLine last August that the London native enlists his boarding school classmate, Julius Kent (Owain Yeoman), to help in the investigation.

“It’s a fun and very colorful role,” Doherty said of Yeoman’s character.

In his interview with TVLine, Doherty suggested that the financial analyst murdered in the episode “was looking for better and more efficient ways to identify what are known as Earth-killer asteroids.” Doherty added that the episode features “a mystery on top of mystery as to why anyone would want to kill someone who might be able to help NASA locate and, hopefully, divert a small planetoid hurdling towards Earth.”

In the same episode, Captain Gregson (Aidan Quinn) lobbies to include Sherlock and Joan when his unit is chosen to receive a city commendation for its exemplary work.

Season 5, episode 4 marks “Elementary’s” 100th episode, which the cast and crew filmed a month ago under the direction of John Polson.

“Elementary” Season 5, episode 4 airs Sunday, Oct. 30, at 10 p.m. ET on CBS.  This week’s episode, on the other hand, airs on Oct. 23 in the same timeslot. Check out the synopsis for Season 5, episode 4, titled “Render, and Then Seize Her,” below:

“Sherlock learns a secret about Captain Gregson’s girlfriend (Virginia Madsen) when she hires him for a case she wants kept off of Gregson’s radar. Also, Sherlock and Joan join the NYPD’s search for an abducted woman.”