A line-handling device is for letting out, winding up and locking a line. The line-handling device has: a first handle; a substantially flat reel which is rotatable relative to the first handle; a line-guiding part which is fixed relative to the first handle; a locking mechanism for locking the reel in a non-rotatable position; and an attachment element for a tautening device, the reel being displaceable relative to the first handle parallel to the rotational axis of the reel. A line-handling system is for suspending a line between two anchoring points and a method is for suspending a line between two anchoring points.