Line of Duty: Jimmy Nesbitt, definitely spelt 'definately' and Detective Chief Superintendent Patricia Carmichael - three things you may have missed in season six episode five

*Warning - potential spoilers ahead.*

Jimmy Nesbitt - As DI Steve Arnott (Martin Compston) and DC Chloë Bishop dig into the murder of journalist Gail Vella they stumble across a possible link with the murder of a young black man called Lawrence Christopher and the case concerning Oliver Stephens Lloyd.

Oliver Stephens Lloyd was a social worker investigating allegations of child abuse who was murdered but whose death was recorded as suicide.

DCI Marcus Thurwell (Jimmy Nesbitt) was the lead detective on the Stephens Lloyd case and is suspected of covering it up on behalf of the OCG.

Thurwell, along with current Chief Constable Philip Osborne, and imprisoned former Det Supt Ian Buckells were all involved in the Lawrence Christopher investigation in 2003.

The son of OCG leader, Danny Hunter, is believed to have struck Lawrence on the head with a piece of lead piping, the blow that pathologists believed resulted in his death.

It is believed Hunter bribed Thurwell, Osborne and Buckells to keep his son from being prosecuted.

Thurwell is believed to be on-the-run in Spain.

A while after this revelation, Ted Hastings (Aidrian Dunbar) is seen looking at photograph of himself with fellow constables in the RUC back in the 1980s.

Some fans believe Jimmy Nesbitt's character DCI Marcus Thurwell started out in the RUC along with Ted Hastings but whether the pair were friends or enemies remains to be seen.

Definitely spelt 'definately' - During an online conversation in a secure chatroom between DSU Joanne Davidson (Kelly MacDonald) the elusive H spells definitely incorrectly when they tell Davidson she will "definately" not be asked to do more of the OCG's bidding once she kills DI Kate Fleming (Vicky McClure).

Some believe that this is the evidence that Ted Hastings is actually H because he spelt definitely in the same way in the past.

- Detective Chief Superintendent Patricia Carmichael - The biggest thorn in Hastings' side is back but could she be H?

One Line of Duty fan took to Twitter to post his very own unique theory.

The fan claims disgraced and imprisoned lawyer Jimmy Lakewell (Patrick Baladi) told Steve Arnott to look more into the "race claim".

The fan then said: “Race claim + H” rearranged = Carmichael.

Is this the smoking gun fans have being looking for - only time well tell!