The Ring of the Nibelung: Book One - The Rhinegold #4 (2000)

Votan and Logé were able to swindle Alberich of the Ring, and a mountain of dwarven gold, to boot. But they did not escape before the wicked dwarf cursed the Ring. The treasure they brought back might satisfy the giants holding Freia, who demand that it be stacked high enough that it eclipses the beautiful young goddess from their sight, but a mountain of golden items still has gaps through which a giant might peek--gaps just large enough to fit a Ring!