Yesterday, When We Were Young is a tragic romance novel written by a "Johnston Blasin", the pseudonym of the Nymph Sybil Jenstone?. It was released to the public in 9,991 XA? and has since been widely received by readers. The story talks of the miserable fate of lovers Jess Marrow, a Therian, and Opus Darbough, a Sidhe who had been turned into a Vampire by a jealous former love.

Such is the beginning of the tale, with the opening scene held in Jess' sitting room where Opus had asked her hand for marriage. In a sick twist of fate that sets the pair apart, Opus is bitten by his former love a month before they are to be married in an act of sacrifice to spare Jess from a crueler fate. Pains are taken by Opus to cover his new nature and, in so doing, he breaks his ties with the female Therian in a bid to save her from the truth and a miserable life with a vampire.

Years pass and yet still neither can forget the other. Opus has since lived through the leash of his former lover while Jess has found a second love, a wealthy Therian popular in the crystal mines, to whom she bears a son she names Mopus after her first love and her broken heart. A series of events bring the two back together when Opus rescues her son from a raging storm. They first act cordially to each other, with Opus becoming a welcome guest in the Therian's home, but they soon cheat on their partners to resume their broken love, which persists beyond Opus' new nature. The treachery is later discovered, which leads to the deaths of Opus' former love, Opus himself, and Jess after she and her true love fling themselves off the mountain. The book ends with Jess' husband living a quiet life with his son as he reflects on the mistakes he made to lose his wife.

The book is known to be particularly popular among Vampires who feel that some justice has been done on their part, and is only moderately so among Therians for the conflict that exists within the novel. It is found among easily accessible shelves around Elysia?. Sybil Jenstone, on the other hand, died before she could reveal the real Johnston Blasin, leaving her son, Basil Jenstone?, to take up the pseudonym for himself to protect his mother's secret. Rumors have it that he is writing a sequel with Mopus as the leading character.