As Holby City fans will know, Doctor Arthur Digby has been dating fellow medic Morven Shreve (Ellie Fanyinka) for a while now.
However Morven was recently left shattered when she learned that her father, Austin, needs an urgent liver transplant - or he’ll die.
In a bid to prove his love, Arthur has offered to undergo compatibility tests to see if he could be a donor.
But, during the tests, his colleague, transplant coordinator Essie, spots an irregular-looking mole on Arthur's back.
Fearing it could be cancerous, she urges him to have it checked out - something which Arthur doesn’t want to hear.
He told What’s On TV: "Arthur thinks Essie’s just being over-protective; he's never really noticed the mole before and reckons it's probably nothing.
“He really doesn't want to be dealing with this right now – he just wants to push on with being the saviour of the day, which he's never been before."
However Essie, truly concerned, calls on Hanssen to come and give a second opinion.
And it seems as if Arthur’s mole could be far more serious than he thought.
"When Hanssen orders for the mole to be removed and examined to find out if it's cancer, Arthur feels like the rug has been pulled out from under him and all his plans are put on hold,” explained Rob.
“He's shocked that it now looks like he's dealing with something much more serious. He shuts down and doesn't tell anyone about it… especially Morven."
Could Arthur have skin cancer?
Holby City continues Tuesdays at 8pm on BBC1.