In Wanheda (Part 1), Roan, along with a few other Grounders, enter Niylah's trading post, and she asks him if he has something to trade. Instead, he pulls out a sketch of Clarke, who he recognizes as Wanheda. He asks Niylah if she has seen Clarke and Niylah lies, telling him that she was there two days ago. Roan thanks her for being "more help than she can imagine," and proceeds to leave. On his way out, however, he glances again at the red-headed girl, who is really Clarke, standing in the corner of the trading post with a suspicious look on his face. Later that night, Clarke leaves the trading post, believing Roan to be gone, however, Roan appears from behind some trees. He grabs Clarke and holds a knife to her throat.
In Wanheda (Part 2), Roan drags Clarke along a riverbank on a rope. She collapses of fatigue despite his demands for her to stay on her feet. He sarcastically replies that Wanheda is human after all. He kneels to fill up his water bottle but Clarke tackles him into the water from behind. She holds him under for a long period of time, attempting to drown him, and eventually releases her grip on him when she believes him to be unconscious. He jumps from the water and holds Clarke's head under water until she stops struggling. Clarke comes back up with the red berries rinsed from her hair to see that Roan's face has also been cleaned, revealing Ice Nation scars upon his face.
In a vast field, they encounter three Ice Nation scouts and Roan tells Clarke to stay quiet so they can slip away unnoticed. Clarke disobeys his orders and screams, alerting the scouts. tells her their deaths are on her as he puts a sack over her head. He walks Clarke up to the warriors, claiming that he doesn't want any trouble and that he has a Wanheda for their Queen. One of the warriors lifts the bag from Clarke's head, confirming that it is her. Clarke starts running with one of the scouts chasing after her while Roan fights and quickly dispatches the other two, grabbing a bow and arrow along the way. He shoots the third scout in the back, causing him to collapse on top of Clarke. As Roan goes to retrieve Clarke, she sneaks a weapon from the dead scout and stabs him in the stomach with it but he quickly subdues her.
Roan takes Clarke to an abandoned subway station and warns her that if she screams, this time, they will both be dead. He ties her up in the station and heats a blade over the fire. He takes off his shirt to treat his wound, showing impressive scars across his back. He mentions if she had stabbed an inch deeper he would be dead, and that maybe she isn't the Commander of Death after all. Clarke asks why he is hiding from his people and he asks her why she ran away from hers. He cauterizes the wound on his side and walks over to Clarke with the heated blade. He calls her "the Great Wanheda, Mountain Slayer." She asks him why he is taking her to the Ice Nation when he isn't loyal to them and her people will offer him more. He tells her that he was banished and she is the way back to his people. Bellamy arrives at the subway station and finds Clarke tied up. They are briefly reunited before Roan has him pinned to the ground and is about to kill him when Clarke pleads for his life and promises Roan she will cooperate if he lets Bellamy live. Roan stabs Bellamy in the leg so he can't follow after them and takes off with Clarke again, leaving Bellamy behind.
Roan brings Clarke into a room with a bag over her head. The bag is removed, revealing Lexa seated on a throne with Indra and Titus flanking her. Roan tells Lexa to lift his banishment as payment on the bounty. Lexa tells him his mother's army is marching on Polis and she will honor the deal when Roan's queen honors her coalition. She commands "Prince Roan of Azgeda" to be locked away.
In Ye Who Enter Here, in Polis, Clarke is approached by Roan, who is also being kept prisoner by the Commander. Roan tells Clarke that Lexa broke the deal with him by not lifting his banishment when he delivered Clarke to her and now he wants to strike a deal with Clarke. He bought off some of the guards and has left a knife under Clarke's bed to kill Lexa and with Lexa dead, the Ice Queen will become ruler of the Coalition. Clarke says she sounds worse than Lexa but Roan tells her it is because she only has heard Lexa's side of it.
In Watch the Thrones, Clarke encounters Roan and tells him not to kill Lexa, he tells her he can't but instead offers her a way to kill Nia. The plan fails the match still takes place. Roan and Lexa appear to be rather evenly matched, with Roan initially taking the upper hand. However, Lexa counters and is able to regain dominance. Clarke watches Lexa pin Roan down and prepare to strike but instead she throws the spear at Nia, killing her instantly. Roan is then crowned king of the Ice Nation.
In Stealing Fire, Roan admits to Clarke that he would accept if Ontari became Commander because she was Ice Nation. He helps Clarke and Murphy escape Polis through the tunnels but informs her the next time they meet it won't be as friends. Clarke goes to steal the Flame and is later named the Flamekeeper by Titus.
In Perverse Instantiation (Part 1), Roan saves Clarke's life when one of A.L.I.E's chipped victims tries to kill her to get the flame. They then become allies because they both have the same common goal of getting the Flame to Ontari. They arrange a ruse where Clarke acts as Roan's prisoner and they enter the Polis square with the Flame. However, Roan is shot by Kane and Clarke is taken by Jaha and Abby and the plan is a failure.