Two conditions must coincide: the president withholds a signature through the ten-day period, and congressional adjournment prevents return. Inaction alone is insufficient. When return remains possible, the same passage of time produces law without a signature.

The pocket veto ends the bill because Congress receives no returned measure on which to vote. Legislators must begin again with new legislation rather than attempt an override. This consequence makes the nature and timing of the adjournment central.

A scenario should be analyzed from constitutional facts, not the president's label. Ask when the bill was presented, count ten days excluding Sundays, and determine whether Congress had an authorized means to receive a return.

Video lesson: How a Bill Becomes a Law: Crash Course Government and Politics #9