Lyric discussion by dcba 

Cover art for End Of A Spark lyrics by Tokyo Police Club

i think christa has it right... although i also wonder if the "spark" could mean life itself-

we think of our own life as a comparatively long time, measured in many decades. but even a very long life, measured in terms of the life of the earth or the universe or "eternity," is really a tiny spark- here and gone in an incredibly short instant.

so i wonder if that is part of the image in the song as well- that whatever period of our lives we look at- innocent childhood, or the whole thing- it is a preciously short flash, or spark, and then its gone.