Gene Wolfe's An Evil Guest is set in the retro-pulp future in which a cure for cancer has allowed people to start smoking noirishly again. It features a hard-boiled cop, a crime fighter with mysterious powers, a luscious, spunky redhead with the pulpy alliterative name of Cassie Casey, a shadowy figure with the power to cloud men's minds, a werewolf, Rusterman's (Nero Wolfe's favorite restaurant), beautiful downtown Kingsport, Miskatonic University, and an annoying Squid God. And the popular alternate universe restaurant chain, International House of Toast.
It's a richly allusive pulpiverse in which pulp genres bleed into each other, and the author plays with genre tropes of secret identities, lurking tentacled horrors, god-like aliens and leathery wings against the moon.
As much as Wolfe admires Lovecraft, in his fictional universe leathery wings against the moon may belong to creatures that are not canonical Lovecraftian horrors.
On top of this, Gene Wolfe weaves in some other issues. Good, evil, and our relation to God, not to be confused with merely god-like alien entities. But also a collective mythology that predates the pulps by centuries, recorded in the fairy tales of the Brothers Grimm. In the novel, on the planet Woldercan the first and most useful warning is "Don't go into the forests". Sound familiar?
But of course Wolfe knows that in spite of all the wise warnings, people will insist on going into the forest, because if not there will be no story. So this advice follows: "If you absolutely have to go, take take a couple of old hands with you. At least two. More would be better."