Written by the band's lead vocalist Will Gould and guitarists Ian Miles and Sina Nemati, the Callous Heart was Creeper's first release since signing with major label Roadrunner in June 2015.

It was the group's last release with Sina Nemati, who left in December, and the first with keyboardist and vocalist Hannah Greenwood who joined at the same time.

[2] Speaking to Upset magazine shortly after the announcement, vocalist Will Gould described "Lie Awake" as "the ultimate Creeper song",[3] as well as explaining to Kerrang!

[7] In promotion of the EP, Creeper supported influential horror punk band Misfits on a UK tour in August, followed by a number of shows with emo group Moose Blood in September.

[9] Creeper's second EP was their last release to feature guitarist Sina Nemati, who left the band in December 2015 to focus on his career as an audio engineer in London.