Highlander: The Animated Series - Season 1 Episode 4 Melvyn the Magnificent

Ramirez takes Quentin and Clyde to an old mining complex to meet his Immortal friend Erol, an expert in explosives, oil and mining. However, they only find Erol's traumatized, delusional and unhinged mortal assistant Melvyn there, who has, in his madness, convinced himself that he too is one of the Immortals. He abuses their trust to trap them in the mine, kidnaps Clyde thinking she's his dead daughter and takes her with him to Mogonda on a suicide mission of revenge to kill Kortan with Erol's explosives.