Actors Clark Gregg and his wife Jennifer Gray pose during Amazon's premiere screening of the TV series "Transparent" at the Ace Hotel in downtown Los Angeles, California, September 15, 2014.
Actors Clark Gregg and his wife Jennifer Gray pose during Amazon's premiere screening of the TV series "Transparent" at the Ace Hotel in downtown Los Angeles, California, September 15, 2014. Reuters/Kevork Djansezian

"Marvel's Agents of S.H.I.E.L.D." Season 2 finally returns with its much-awaited Episode 9 on Dec. 2. The show features some highly anticipated moments as Phil Coulson's team of crime-fighting agents continue their quest to find the hidden city and the answers to the alien writings. Here are a few spoilers on 'Marvel's Agents Of S.H.I.E.L.D.' Season 2 Episode 9 titled "Ye Who Enter Here." [Warning: Spoilers Alert!]

In the last-aired episode, the agents made some baffling discoveries during their mission to locate the hidden city. Bakshi's interrogation resulted in the discovery of Whitehall's real identity. The S.H.I.E.L.D. Agents realised that Whitehall is actually Reinhardt, who is more than 100 years old. He was taken into custody by Peggy Carter but he managed to escape from jail. Later, he found the secret to stop aging. This is the reason why he looked younger than his age.

It is said that the woman whom Whitehall killed to stop aging and have a long life was Skye's mother and the Doctor is Skye's father. After losing his wife to Whitehall's evil intentions, the Doctor vowed to avenge the death of his lover. Furthermore, Grant Ward met up with his elder brother Senator Christian and tortured him. Grant Ward chased Whitehall in an attempt to become his ally. Meanwhile, Phil Coulson and his team figured out the secret of unlocking the hidden city. They learned that only Obelisk and Diviner can take them through it.

Spoilers on Episode 9 of "Marvel's Agents of S.H.I.E.L.D." are already swirling around. Marvel has released the first trailer of "Ye Who Enter Here" on its official YouTube channel, teasing an exciting story arc. The scene features Skye and May;s combat. The clip opens with Raina and Koening waiting in the safe house. Meanwhile, Skye knocks the door and tells them that they need to move. While moving out, May attacks Skye and tries to stop her. The two get into a physical fight.

Another sneak peek published on Spoiler TV shows the big revelation. Coulson announces the location of the hidden city is Puerto Rico and the entry to which is from San Juan. In the race, S.H.I.E.L.D. agents manage to beat HYDRA and find the city, but their challenges only increase knowing that Obelisk is in the hands of HYDRA agents.

As per the synopsis of "Ye Who Enter Here" published on ABC's official site, the agents manage to reach the city before their enemies do. However, accomplishing the mission and unveiling all the secrets associated with the mysterious city demands more than anyone may have imagined. The team faces their greatest challenge yet when they have to make an "ultimate sacrifice." Meanwhile, Whitehall is chasing Raina and May and Skye must get to her before he does.

In the side note, the upcoming segment was written by Paul Zbyszweski and directed by Billy Geirhart. "Marvel's Agents of S.H.I.E.L.D." stars Clark Gregg as Phil Coulson, Brett Dalton as Grant Ward, Chloe Bennett as Skye, Ming-Na Wen as Melinda May, Elizabeth Henstridge as Jemma Simmons and more. Season 2 Episode 9 "...Ye Who Enter Here" airs Dec. 2, 2014 at 9 p.m. ET on ABC.

Video: Agent Skye Faces a Familiar Foe - Marvel's Agents of S.H.I.E.L.D. Season 2, Ep. 9 - Clip 1

(Credit: YouTube.com/Marvel Entertainment)