Power to a light, through two lights and then to a switch
If you are in the U.S.A. and the wiring was installed before 2011, it probably looks like this. Note the colored tape or paint mark on the white wire used as a switched hot:


NEC 2011 and later calls for a neutral wire to be present in each switch box (to accommodate smart switches) so if your wiring is new it might look like this: