Borderlands - Fran March

Elves tie a pretty knot, making things seem other than they are. . .

A dangerous power burns in a deep cavern where the Blācencynn keep the North Gate closed, guarding the Mortal realm against Dark Faerie.

Lord Soulis of Liddesdale must honour a grim contract made with Robin Redcap, Prince of Spriggans: destroy the Blācencynn and open the North Gate.

The gentle healer, Lord Rædwulf Blācencynn, and his younger brother, Penda, together with the elf, Lord Adan, and his bowman, Hirnac, set out to close it and prevent Redcap from opening the South Gate at the Mereburg. The mortal man, Thomas Learmont, must help them if he wants to escape Bright Faerie and return to his world.

This is Borderlands, a tale drawn from British folklore.