This week in London, ambulance driver Lee picks up a senior citizen and regular Blue Cross patient - 17-year-old tabby Twinkle - who has a sore mouth. Elsewhere in the capital, vet Roshene is heading up the mobile clinic and sees bulldog Ace who has a nasty swelling and is immediately transferred to the hospital for surgery - where vet Aysha find a surprising reason for his swollen face.  In Grimsby, volunteer Helen has taken a very special delivery and is caring 24/7 for a litter of one-day-old Staffie pups, and vet Natasha is dealing with a puppy who has been eating cotton wool.