23. Episode 23
For the new series' first episode, Mariella Frostrup (right) is at the 60th Cheltenham Literature Festival.
24. Episode 24
Iranian-born comedienne Shappi Khorsandi, veteran journalist Harold Evans, and Melvyn Bragg
25. Episode 25
Ian Rankin and Tracy Chevalier
26. Episode 26
Dr Brooke Magnanti, 34, works at St Michael's Hospital and wrote best-selling books about her time as a prostitute as she struggled to make ends meet. Also, Booker Prize-winner Hilary Mantel.
27. Episode 27
John O'Farrell, Conn Iggulden, and Alison Weir
28. Episode 28
Michael Palin, Andrew Marr, and John Banville
29. Episode 29
At the start of a new run Mariella Frostrup recaps some of the highlights from the series that has got people talking about books again. These include conversations with Dr Brooke Magnanti, the real-life Belle De Jour and inspiration for Billie Piper's character in The Secret Diary of a Call Girl, Ben Elton, Sue Townsend and Robert Harris.
30. Episode 30
Robert Harris, William Boyd, and Lynn Barber
31. Episode 31
Looking back over the best bits from the first half of series four. Patricia Cornwell, Sue Townsend, Ian Rankin, and the almost ubiquitous David Mitchell all pop in for literary chat.
32. Episode 32
No details
33. Episode 33
Antonia Fraser, Ian McEwan, and Joanna Trollope
34. Episode 34
Fantasy sage Terry Pratchett. Orange Prize-winner Andrea Levy discussing her new novel, The Long Song. Marina Lewycka talks about the inspiration for her book We Are All Made of Glue. Plus, Sebastian Barry takes us to Ireland and the place where he wrote his prize-winning novel The Secret Scripture, and we discover Cherie Blair's bedtime reading.
35. Episode 35
Philip Pullman, who is creating a stir with his new book about Jesus. Pullman retells the gospels with Jesus and Christ as brothers and two distinct characters. Rose Tremain talks about the follow up to her Orange prize winner. Plus, Lemony Snicket with his bedtime reading suggestions and award-winning debut novelist Neel Mukherjee.
36. Episode 36
Upper-crust socialite and interior designer Nicky Haslam recounts anecdotes from his biography, and thriller writer Philip Kerr recommends reading Michel De Montaigne's essays when you are "feeling a bit thick". Monty Don talks about gardening, and a dry and unflappable Lionel Shriver talks about the American healthcare system in relation to her new novel, So Much for That.
37. Episode 37
John Boyne, author of The Boy in the Striped Pyjamas; American novelist Joshua Ferris; and politician Shirley Williams
38. Episode 38
Roddy Doyle on his fictional trilogy exploring what it means to be Irish; feminist Natasha Walter on the hypersexual society; John Lanchester on his bedtime reading (Tolstoy); and Martin Amis on women's liberation, the sexual revolution and autobiographical fiction.
39. Episode 39
David Nicholls, Alistair Campbell, and Simon Kernick
40. Episode 40
Authors George Pelecanos and Joanne Harris, and poet Simon Armitage
41. Episode 41
Blake Morrison, Maggie O'Farrell, and Ben Macintyre
42. Episode 42
Episode 24 "final episode of the series" - Professor Robert Winston on liabilities, Joseph O'Connor on love stories, and Jonathan Coe on loneliness. Plus, Martina Cole talks trade secrets.
43. Episode 43
The Book Show at Hay: Turner winning ceramicist Grayson Perry, journalist Tony Parsons, and well travelled honorary Englishman Bill Bryson. Plus contributions from Jerry Hall and Beth Orton.
44. Episode 44
The Book Show at Hay: Carlos Ruiz Zafon, Nadine Gordimer, and Christopher Hitchens. Music from Alex Valentine.
45. Episode 45
Antony Beevor replacing Gary Kemp on the show tonight. Other guests are Audrey Niffenegger, Jo Brand & Dennis Rollins.
46. Episode 46
Simon Schama, Joss Ackland, and Rob Brydon are the guests on Mariella's sofa today. Music from Thea Gilmore.
47. Episode 47
The Book Show at Hay: William Dalrymple, Jacqueline Wilson, and Sir Ian Blair. Music is from the ever excellent Orquesta Buena Vista.
48. Episode 48
The Book Show at Hay: Louis de Bernières, who has taken a shot at writing about rural England in the 1960s in his new book, Notwithstanding; Allegra Huston, author of the memoir Love Child; and the current children's laureate Anthony Browne.
49. Episode 49
The Book Show at Hay: Brian May, Virginia McKenna, and Alexander McCall Smith talk animals, including a dog bugged by MI5. Music from the truly brilliant Toumani Diabate, and mathematician Alex Bellos teaches us how to cut a cake in a mathematical fashion.