Abstract: There are disclosed two embodiments of an overshot tool for use in recovering a fish within a well bore, wherein a radially expandable and contractible grapple having helical tapered outer surfaces is seated upon a bowl within an intermediate portion of a tubular body on which the tool is lowered over the upper end of the fish, thus enabling the grapple to be lowered about the upper end of the fish and the teeth about its inner diameter to bite into the fish. A control assembly packer having a metal body mounted beneath the grapple has tangs for extending into slots in the body and grapple to limit the rotation between them, and the packer assembly carries a seal ring for sealably engaging the fish, which is held in place by means of a retainer ring threaded to the metal body of the assembly supported within the bore of the body.