In the novel Ordeal by Innocence, Ernie was mentioned by Micky Argyle, when Micky was a child.
Leo Argyle remembers an incident which happened when Micky was a child, who had been evacuated to the war nursery run by Rachel Argyle. Micky had cried out one night that he wanted to go home, to "our Mom and our Ernie".
The text does not explain exactly who Ernie is, and there is no further mention of him. He is unlikely to be a romantic partner of Micky's mother, as she would always ask him to address her partners as Uncle. It is possible that Ernie is a friend or relation of Micky's, or even a pet.
If Mickey grew up in the north of England “our Ernie” might indicate that Mickey and Ernie are brothers, as our in norther english might indicate that the person mentioned belongs to one's family.[1]