The book Keith looks at and throws aside after playing with the snow globe was Star Trek: The Wrath of Khan.
Madeleine Madden (Corrie) and Jon Prasida (Lee) previously worked together on episode 1.5, Blank Canvas (2015), of Ready for This (2015) as Zoe Preston & Derek respectively.
Jon Prasida (Lee) & James Stewart (Colonel) also appeared in Hiding (2015) together as Garys and Troy Quigg/Lincoln Swift respectively.
Deborah Mailman (Kath) & Richard Young (Jack) also worked together on episode 2.8, Two Different Places (2011), of Offspring (2010) as Cherie Butterfield & Adam respectively.
James Stewart (Colonel) & Narek Arman (Homer) previously appeared together in episode 6.12, Packing Up the Rafters (2013), of Packed to the Rafters (2008) as Jake Barton & Jackson Radovic respectively.