Ottar was a gangster from the city of Strand and lieutenant of the Mársmidr gang. As such, he dealt with whatever problem their leader Kjallak wanted to be resolved. His life of crime took some toll on him, permanently scarring his face from the brow to his chin.
About four months before the Third Great War, the Mársmidr leader Kjallak desired to acquire the Gift of Hadrborg. Ottar soon sent two men under the command of Johan to steal one half of it from the varl Olaf. After succeeding however, Johan went to Halsar and tried to blackmail his gang into letting his brother Hallvard, who had to flee after stealing their profits, back in. Ottar then sent Skoegir to assassinate him and retrieve it from him, which he was successful in.
Kjallak then sent Ottar and a few other men after the varl Ulfvalgr, who was going after the amulet's thief, in order to get the other half he believed he possessed. Since not even Ottar knew what exactly they were looking for and Ulfvalgr never actually had it, they were exposed while trying to rob him. Ulfvalgr slew the man who was searching through his possessions and fled to Karlshus.
As Ulfvalgr fled to Karlshus, Ottar and his men tracked him to Broddi's Mead Hall. The varl however pretended to get in a fight with Olaf, who had also arrived there to find the stolen half of the amulet. This resulted in a bar brawl which allowed Ulfvalgr to get away, and he left the town with Olaf and Stefnir. Ottar and his men soon realized that they had fled together, and forced the establishment's owner Broddi to tell them about his dealings with Olaf, after threatening his daughter. After learning Olaf was going to Strand, they burnt down the mead hall and cornered Hallvard, whom they discovered was there too. Ottar offered to have him forgiven and tempted him with meeting his brother again, if he followed Olaf and Ulfvalgr and made sure they were caught by Kjallak.
Hallvard succeeded in his mission of keeping Olaf and Ulfvalgr alive till Kjallak lured them to his hideout at the mead house called The Shattered Shield. The plan however soon went sideways as the Governor's Guardsmen Eirik and Valgard, whom he had allowed to follow him in order to help him keep them alive, crashed into the mead hall and rescued them from the Mársmidr. Kjallak after learning from his scout how they came to know about his trap, punished Ottar by taking the ring finger from one of his hands. Meanwhile as the two were talking, Hallvard had learnt about Johan's death from Ottar while spying on them, and decided to expose the Mársmidr by going to the warehouse of their allies called the Vak'auga at the western docks.
Eirik and his new allies soon discovered that Kjallak was smuggling in varl skeletons after going to the same warehouse where Hallvard had went, being directed to go there by the Vak'auga spymaster Leiknir. They also rescued Hallvard, who had been captured by the Mársmidr and badly mutilated, and he decided to join them in taking down the gangs. Eirik also found that the Aetla Hilmir, the Mársmidr and the Vak'auga were allied together, and decided to lure one of their lieutenants by getting Olaf and Ulfvalgr out in the open, knowing they would only send a trusted man of theirs to the match. Kjallak deployed Ottar to take some of the gang members and varls of the warlord Vilmundr to the tournament, but they were defeated.
The Aetla Hilmir ambushed the tournament after Eirik's team won, but Eirik had Hallvard, Olaf, Leikir's aide Runa and Stefnir escape with Ottar, while he held them off with Ulfvalgr before they both escaped as well. At the hideout Eirik and his allies were staying in, Hallvard tortured Ottar brutally and inflicted every injury that had been inflicted to him by Skoegir earlier. Ottar begged him to let him go and told him where he could hopefully find Magnus or Kjallak. When Hallvard rejected it, Ottar tried to tell him that Skoegir had killed his brother, but he stated he already knew about Johan's death. The prospect of taking down Skoegir however was enough to make him agree to release Ottar to Eirik.
After learning that Ottar was willing to cooperate, Eirik warned him that he would still have to serve a severe sentence, even if he took him under his protection. Ottar however stated that he did not care about it, since he only wanted his torture at Hallvard's hands to end. He then told them that the Vak'auga were smuggling in an important shipment for the Mársmidr at the Ninth Pier, and stated it might be their best bet to capture Magnus or Kjallak. Eirik wanted to get the City Watch of Strand involved, but the others decided to go without him as the guards had failed them repeatedly in past.
As Eirik's allies took the yoxen cart, he was forced to take Ottar to the Great Hall on his own. He crafted a sled to ensure they arrived in time, so he could alert the Governor's Steward Olvir about the triumvirate smuggling goods at the Ninth Pier, and have the City Watch attack them. Eirik then asked Olvir to have Ottar taken to the menders for healing and place him under protection. Olvir did as Eirik requested, and he was later imprisoned.