Isaac Mayfield (Marc Elliott reprising the role) was ousted from Holby in disgrace two years ago after putting his then boyfriend, medic Dominic Copeland (David Ames), through a lengthy campaign of emotional and physical torment.

But, in a moment of madness, Dom contacted his former lover, who immediately turned up at Holby. Oh dear, Dom, what have you done?

This week, Isaac’s back again, this time with his dad, Jon, who needs urgent medical attention – and he’s hoping Dom can help. Dom’s colleagues Sacha Levy and boss Henrik Hanssen are unimpressed to see Isaac back at Holby after all the trouble he caused and try to have him ejected. Dom’s mum Ange even threatens him!

Having spent time in prison, however, Isaac insists he’s now a changed man – he’s even written a book titled ‘The Man I Was’. Can Isaac convince Dom and everyone else at Holby that he’s turned over a new leaf?

Meanwhile, Jac gets a shock when a former heart patient, Ken, turns up to do a presentation for new state-of-the-art life-saving equipment. Both Ken and his C-Arm machine aren’t without their faults. But can he convince Jac to sign on the dotted line?

Holby City continues Tuesdays at 8pm on BBC1.