In the two @-@ part finale to series two , " Counterfeit " ( 1994 ) , James Horton ( Peter Hudson ) , a renegade Watcher who believe all Immortals must be eliminated , use killer Lisa Halle ( Meilani Paul ) to try and kill MacLeod . Lisa undergoes plastic surgery to resemble Tessa and therefore is played by Vandernoot from that point on . MacLeod meet Lisa just after he admitted to himself how much he missed Tessa , and he is stunned by her resemblance with Tessa . Despite knowing that Tessa is dead and cannot return , he eagerly pursue a relationship with Lisa . He eventually admit the truth when he discover a scar on Lisa 's jaw . Horton kill Lisa on Tessa 's grave before being himself killed by MacLeod .