The ornamental design for a fireplace, as shown and described.
FIG. 1 is a front perspective view of a fireplace showing my new and original design;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a right side elevation view thereof; and,
FIG. 4 is a left side elevation view thereof.
The bottom and back sides of the Fireplace form no part of the claimed design. The broken lines in the drawings and the space within the broken lines represent environmental subject matter that forms no part of the claimed design.