While filming the scene in which Jack first tries the Resurrection Glove on one of the murder victims, John Barrowman accidentally said "maximum erection time", bringing production to a standstill until everyone recovered.
Yasmin Bannerman previously starred in the 2005 episode of Doctor Who 'End of the World' as Jabe (representative of the Trees aboard platform 1)
While Jack and Gwen are talking in Jack's office, you can see a pair of 3D glasses hanging from Jack's lamp shade. These are at least a reference to The Doctor's 3D glasses, if not actually his.
The ferry in the closing sequences of this episode was a CGI creation.