The upcoming episode of "Big Bang Theory" season 9 will re-examine the friendship between Sheldon and Leonard as the two find themselves entangled in a row.

Based on the synopsis for episode 21 of the series, Sheldon and Leonard will get involved in a heated argument as they host a viewing party for the entire gang.

The episode, titled "The Viewing Party Combustion," will see the gang getting together for the premiere of "Game of Thrones." However, what's supposed to be a viewing party will turn into a squabble between old friends Sheldon and Leonard. Synopsis for the episode says that things will start out small, but everything will be blown out of proportion because of Sheldon.

Spoilers for the episode suggest that the argument between the two buds will arise from Sheldon's insistence to keep the roommate arrangement meeting.

As the argument escalates, loyalty of the other members of the gang, Penny, Howard, Raj, Amy and Bernadette will be tested as they are forced to take sides between the two. It looks like the other friends will find Leonard as the obvious choice, as he, unlike the loud-mouthed Sheldon, does not make life difficult for them.

Promotional photos for the upcoming episode show that Penny will take the side of Sheldon while Amy will take that of Leonard. The group will be divided into two camps and will stay in two different rooms--4A and 4B.

The party ends with Howard being rushed to the hospital after eating peanuts.

"The Viewing Party Combustion" airs on April 21, 8:00 P.M. on CBS.