It is claimed that The Last Door is loosely based on the works of Howard Phillips Lovecraft.
H. P. Lovecraft was born in 1890. He is best known for his writing about horror, fantasy and science fiction. In the pages of Weird Tales and other pulp-fiction magazines of the 1920s and 30s, Lovecraft pioneered a new type of story that fused the thrills of supernatural horror with the visionary concepts of science fiction. He shaped the genre cosmic horror and revolutionized the modern horror tale through its depiction of a vast universe indifferent to human existence. Where far superior extraterrestrial beings decide over humanities fate. Some of his most popular works are part of the Cthulhu mythos.
Links between Lovecraft's work and The Last Door
Both H. P. Lovecraft and The Last Door refer to Lully. He is mentioned in the Lovecraft short story The Case of Dexter Ward. In The Last Door mythos, it is Lully's serum that initially lifted the Veil.
The Beast in the Cave vs My Dearest Visitor: The cavern scene.
In Chapter 6, Wakefield is exploring the caves beneath Wright's mansion to find answers regarding the Veil and Devitt's whereabouts. As he dwells deeper in the caverns he notices that he is the only one walking in the dark. There's another non-human-being present, who is coming closer and closer. Nonetheless Wakefield dwells deeper and deeper. Just as he reaches the altar or portal where Hugo went to the other side, he is jumped by a creature resembling a giant hand. The beast utters a humanoid shriek before it reaches Wakefield. In the following chapter we hear Wakefield running for his life and jumping in the sea to escape from the beast. This tale is quite similar to Lovecraft's The Beast in the Cave. In this tale, an adventurer loses his group and his guide in a large cavern complex. His torch is almost out of fuel and he starts losing his mind. When he recollects himself, he suddenly hears something approaching. His first reaction is that he is being rescued by the guide. But not long after he distinguishes a paw-like walk. He is afraid that a mountain lion is approaching. The torch is completely drained at this point. He presses himself to the wall and in the hopes that he will not be discovered. But he realizes that his scent is way too obvious in a region absent of other scents. He somehow finds some sharp rocks, which he hurls at his predator. He hits the target and when the tour guide finds him and illuminates the predator. It appears to be a man who lost his humanity long time ago by a being lost in the caverns.
In Chapter 2, Devitt found a magazine at St. Gall Hospital entitled Weird Tales. Weird Tales is a horror and fantasy fiction magazine that originally ran from 1923 to 1954 and which has been revived on numerous occasions. Many of Lovecraft's short stories were originally published in Weird Tales, including The Rats in the Walls (1924), The Call of Cthulhu (1928), The Dunwich Horror (1929), and The Haunter of the Dark (1936).
Mysteries of the Worm (De Vermis Mysteriis)
In Chapter 5, Wakefield investigated Paul Street 26, one of Alexandre's London residences. On a bookshelf, he found "doubtful treatises in chemistry and alchemy." Among those books was Mysteries of the Worm by Ludwig Prinn. The book is actually a fictional creation by novelist Robert Bloch, who included it his short story The Shambler from the Stars (1935). The book is described as containing spells for summoning strange creatures. On Lovecraft's advice, Bloch used the Latin form of the title, De Vermis Mysteriis. Lovecraft also referred to the book in his own short stories The Haunter of the Dark (1936) and The Shadow Out of Time (1936). It has been mentioned in several other works of fiction, including The Invaders by Henry Kuttner (1939), The Adventure of the Six Silver Spiders by August Derleth (1950), Jerusalem's Lot by Stephen King (1978), the computer game Alone in the Dark (1992) and the film Hellboy (2004).