=== Family ===
==== [[Sheriff James]] ====
Mark's Father is a local Sheriff. He is a good father to Mark and is always there when he needs him. He is hard on Mark when he suddenly has no interest in going to college, despite the fact that colleges were clawing at each other and even offering generous scholarships to have him attend.
Mr. James grows furious when he catches Mark snooping in his office stating that the investigations there are a matter of national security. He later asks Mark not to get any bright ideas running away with his classmates (John and Sam) when they escape Dumont.
==== Mother ====
Not much is known about Mark's mother, other than the fact that she is staying with family in Cleveland after the fire at her home. Extended company with her mother-in-law is suggested to be the main reason for this. Mark says that she has been weird and distant since the fire but he hopes that she will return once everything has blown over.
==== [[Nana James]] ====
Sheriff James' mother, gives them a home since the house fire. She keeps them well fed and tries to ensure that everyone is happy and safe.
==== Abby and Dozer ====
Mark's pet dogs. Abby is a golden retriever and Dozer is his bulldog.
===[[Sarah]]===
Sarah is Mark's ex-girlfriend. For a while Mark could not accept that the relationship was over and became overly possessive of her. After the battle and when John leaves, Mark and Sarah become friends again with their mutual experience with the Mogadorians bringing them closer. Mark is still in love with Sarah but has accepted the fact that she loves John. After the battle Sarah was the only person who he could talk about what really happened. After a brief meeting with John, Sarah goes missing. Mark leaves Paradise in an attempt to find Sarah, putting his own life at risk. He emails her daily with updates of his blog hoping one day she might reply. When she finally does reply, he is relieved and asks her to join him in Alabama. They work together on the blog, trying to gather information to help both the Loric and the unsuspecting humans. Their safehouse is compromised and they are ambushed by the Mogadorians. Mark is amazed when Sarah shoots a Mogadorian in the forehead, killing him instantly. Sarah is concerned when Mark's condition starts to worsen after being shot at and forces him to get medicine and let her drive. After the ambush they both head to Lexa, Mark's friend's homebase.
In [[The Fate of Ten]], Mark and Sarah fight well alongside each other, both of them disposing of many Mogadorians. Unfortunately, after the battle, Mark sees Sarah die of her injuries, and becomes desperate, trying to wake up an unconscious Marina.
== Allies ==
===[[Lexa]]===
Lexa, also known as GUARD is a fellow editor of "Aliens Annonymous" blog and a friend of Mark. She has been very helpful in assisting Mark to gather information about the loric, the mogadorians and their allies. When Mark leaves Paradise to find Sarah she sends him a care package. She later sent him a truck when his old one broke down after a being shot at by FBI agents and a safehouse, all of them leading Mark to wonder just who she is. When the safehouse is compromised she instructs Mark to head to her home base. They meet face-to-face for the first time and she reveals that she is a Loric.
=== [[John Smith]] and the [[Garde]] ===
At first Mark didn't like John because he started to hangout with Sarah, his ex-girlfriend. With the help of his friends he once tried to kidnap him and beat him, but John got the upper hand and beat his friends and him and threw them all in a nearby river. His attitude towards John changed when he found out John had saved Sarah and his pet dogs from a housefire. He helped John battle the Mogadorians who had found him at the high school. He promised him that he would keep Sarah safe. Learning the truth about John changed Mark and he continued to gather information about the Mogadorians and Loric hoping to help the Loric beat the Mogadorians.
Except for [[Number Six]] and [[Marina]], he has not met the rest of the Garde. In [[The Fate of Ten]], Mark also meets [[Adamus Sutekh]], and at first is shocked to see a Mogadorian on their side. He seems to have taken a liking to Marina, thanking her several times for healing him in battle. He later fights alongside Adam and the others in battle, and Adam and Mark help each other save themselves and Marina after Setrákus Ra nearly kills her.
=== [[Sam Goode]] ===
Mark and his bullied Sam because of his interest in aliens. But upon learning that aliens are real his attitude towards Sam changed. He apologized to Sam before he left Paradise. He later broke into his house hoping to find more information about the Loric and Mogadorians.
=== [[Bernie Kosar]] ===
Bernie Kosar or BK is John's Chimæra. Mark first witnessed BK's abilities during the battle of Paradise Highschool. Mark again met BK when Sarah brought him along for protection to Alabama to meet him. BK saved him and Sarah when they were ambushed by the mogadorians. BK expressed concern when when Mark's condition started to worsen after being shot.
== Enemies ==
=== Setrákus Ra and the Mogadorians ===
After learning that aliens are real and some of them are seeking to invade Earth Mark started to gather information about Mogadorians and released them on a blog named "[[They Walk Among Us (Blog)|They Walk Among Us]]" which put him in the crossfires with the mogadorians. The mogadorians tracked him to his safehouse in Alabama and tried to kill him. He managed to escape with the help of Sarah and Bernie Kosar.