The þáttur tells the humorous tale of Thorstein Thorkelsson's encounter with a demon and how he earns his nickname.
[3] After refusing an order from King Olaf not to go to the bathroom at night alone, Thorstein finds a demon in the restroom.
The demon claimed to be Thorkel the Thin, who supposedly died on the battlefield against a king named Harald War-Tooth.
It is revealed that asking the demon to replicate the cry was an attempt to wake the others, which succeeded as King Olaf awoke and rang the bell.
[4] Nordic paganism view on Hel was radically different than the Catholic interpretation of Hell, as a place of torture.
The Tale of Thorstein Shiver has been used to express the "happy necessity of the conversion" attitude depicted towards Olaf and Christianity in the sagas, both as a good thing and none-optional.
As such, the tale can be argued as bridging the gap between pagan and Christian cultures by depicting and incorporating classical Nordic folk-monsters as true catholic demons.