Complex sentence: No explanation was ever given for his disappearance and he was never seen or heard from again until the final episode of the series when Jaz Hoyt reveals Cloutier's fate: he had been carried off by the bikers and sealed into another wall.
Split into simpler sentences: No explanation was ever given for his disappearance and he was never seen or heard from again until the final episode of the series when Jaz Hoyt reveals where Cloutier's body was taken. Cloutier had been carried off by the bikers and sealed into another wall.