Nycklar was the son of the coffinmaker in Jealousy and witnessed the fight between Leo Bonhart and the Rats, where all of them save for Falka were killed and beheaded by Bonhart. Later, he and Goulue gave the Rats a decent burial.
Nycklar was standing around when Bonhart went back into the inn before asking if anyone fancied a horse and some money and Nycklar eagerly stepped forward. Bonhart then gave him orders to ride to Claremont to deliver a letter to the bounty hunter's cousin, Houvenaghel, and then to deliver a letter to Esterhazy in Fano. Nycklar, who'd been eyeing Falka's horse, Kelpie, was quickly told he couldn't choose that one so the boy chose another Rats' horse instead. However, before he took off, he stayed around and saw Falka naked, having been forced to strip down so Bonhart could make sure she wasn't hiding any magical charms before re-dressing. Bonhart, on seeing Nycklar still there, threatened to cut him up if he failed his task and so Nycklar took off to deliver the letters.
After he delivered the letters though, instead of heading straight home he headed to Malhoun, showing off his mount and spending his money on drinks while telling everyone what happened in Jealousy, exaggerating it more and more as the drinks continued. Stefan Skellen, the Imperial Coroner of the Nilfgaardian Empire, who was looking for Bonhart and Ciri, sent some members of his unit to capture Nyclar and bringing him to Rocayne in order to interrogate him, who told him the truth and about the letters, though he didn't quite know their contents. After the interrogation, Stefan Skellen released him and sent some of his men to Claremont and to Fano to investigate on the letters of the bounty hunter.
Afterwards, he made it back home to Jealousy but was plagued by nightmares until he gave the Rats a decent burial in the town's graveyard. He later joined the army but never returned, making many back home believe that he'd fallen in battle.