The final Series 5 episode of the PBS drama 'Downton Abbey' will finally reveal who killed Mr. Green.

From what it looks like, Mr. John Bates (Brendan Coyle) and Anna Bates (Joanne Froggatt) are in some kind of trouble. In a spoiler photo, the two are seen looking weary behind bars.

Carter Matt speculates that this has something to do with trying to cover-up Mr. Green's murder, even though the two are innocent of the crime.

Innocent or not, Mr. Bates and Anna reportedly have gotten themselves into troubled waters and it may be hard for them to escape because of a very important evidence disappeared.

However, suspects of the crime include Mary Crawley (Michelle Dockery) and Mrs. Hughes (Phyllis Logan), who knew that Anna was sexually assaulted by Mr. Green, while Lord Gillingham turned a blind eye even if he knew what was going on because he might have felt ashamed that terrible things are happening under his employ.

On the other hand, Daily Mail speculates that the two might have something to do with the crime; they could have pushed the evil valet under the wheels of a vehicle in London's Piccadilly Circus.

Moreover, Anna seemed like a likely suspect as she was a victim of Mr. Green and killing him will satisfy her appetite for revenge.

Anna was dragged into a room by Green, where she was heard screaming. After the scene, she appeared looking extremely disgruntled, with bruises and cuts on her face while she called for a servant for help.

Meanwhile, John Bates, who was convicted of killing his wife Vera, is also suspected to have killed Mr. Green as in the previous episodes, he told his wife that after knowing about what Green did to her, he bought a train ticket from York to London just so he could carry out the deed.