All set for Halloween, hospital porter Jason Haynes gets the shock of his life when he witnesses a woman battered and bruised being thrown from a car and left for dead outside Holby.

With the woman, drug addict Sian, bleeding heavily from a stab wound, Jason – who has Asperger’s – jumps into action to stem the bleed with his favourite jumper, while medic Xavier Duvall (Marcus Griffiths) calls for urgent help.

As Xavier and Jason’s aunt, consultant Serena Campbell (Catherine Russell), operate on Sian, Serena persuades Xavier to tell her nephew how he’s helped save the day. But as Jason becomes overbearing in wanting to help Sian, an irritated Xavier yells that he’s ‘just a porter’!

Xavier’s concerned, though, when he discovers Sian has a six-month-old baby daughter Kim who’s missing – but an unconscious Sian can’t reveal where the tot might be. Xavier knows, if they can find out who was driving the car Sian was in, they’ll be able to find Kim.

So Jason’s thrilled when Xavier asks HIM to help police examine CCTV footage of the incident and he turns the AAU storeroom into something out of CSI! But it seems Jason can even go one better than that – he’s remembered the car number plate!

Having already helped save Sian, can Jason reunite mother and baby? And have Jason and Xavier formed a bond of their own?

Meanwhile, Lofty, Meena and Leah get stuck in a lift together and unearth some secrets each one of them is hiding.

And Frieda forces Jac and Fletch to face their feelings once and for all!

Holby City continues Tuesdays at 8pm on BBC One