This episode goes behind the scenes of Silence in the Library

The Doctor and Donna are on the set of the eerie Library Planet to confront the monsters of the dark, the vicious Vashta Nerada. There's a look at how these shadowy creatures are created, how a disused library in Swansea became the setting for all the universe's books, how the effects boys and crew take it in turns to fire books in the general direction of David Tennant and how writer Steven Moffat has contributed to the series.