The Second Call is one of the two general or opening keys of John Dee's Claves Angelicae, the forty eight Enochian Calls received through the scryer Edward Kelley in 1584 and published in Meric Casaubon's 1659 edition of Dee's spiritual diaries, A True and Faithful Relation. Dee's own angelic informant, named Illemese in the sessions, describes the nineteen calls together as entrances into the knowledge of the mystical tables, the four Elemental Watchtowers that the sixteen calls following the two openers are used to work.
The Second Call precedes that elemental work rather than addressing any single element or tablet, standing alongside the First Call as one of a pair that opens the whole sequence before the sixteen calls of the Watchtowers and the nineteenth call, which is recited with the name of whichever of the thirty Aethyrs is being worked. Because the two opening calls address the system as a whole rather than any one part of it, they carry a different structural role from every call that follows: general rather than elemental, and spoken first regardless of which Watchtower or Aethyr the working turns to afterward.
The manuscript record for The Second Call, like the rest of the Claves Angelicae, survives through Casaubon's seventeenth century printing rather than only in Dee's own hand, which is part of why the Calls circulated far more widely among later ceremonial magicians than the unpublished De Heptarchia Mystica, Dee's earlier and separate treatise on the day ruling Kings and Princes of Sloane MS 3191.