a one-way ticket

a one-way ticket

If you describe something as a one-way ticket to a particular situation or state, you mean that it is certain to lead to that situation or state. Having strong feelings for someone when those feelings aren't returned can be very painful. It represents a one-way ticket to unhappiness. The secretarial jobs she'd had since leaving college were a one-way ticket to nowhere, professionally speaking.
See also: ticket