As Digital Spy exclusively revealed last month, Hassan recently returned to the Channel 4 show to film a handful of new scenes, which see her dead character Lynsey Nolan appear as a manifestation of Doctor Browning's guilt.
Browning (Joseph Thompson) sees his first vision of Lynsey next week as the antics of his mystery stalker send his stress levels soaring.
However, when Browning looks again, 'Lynsey' turns out to be the new Lindsey (Sophie Austin).
See shots of Karen, Joseph and Sophie on set together below.
Hollyoaks airs Karen's first return appearance on Tuesday, July 2 at 6.30pm on Channel 4.
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