Rob Beckett, Melanie C, Edith Bowman, KSI, MyAnna Buring, Nadia Rose, Jack Garratt, Jim Al-Khalili

Rob Beckett, Melanie C, Edith Bowman, KSI and MyAnna Buring join Tim and Simon, with music from Nadia Rose and Jack Garratt. Plus: Simon cooks duck in chraimeh sauce; and Jim Al-Khalili talks physics.