a time traveler
must have three hearts
one for the past
one for the present
one for the future
each beats fully
only in the era visited
my ribcage is too small
to contain twelve chambers
and i am going to have
to decide when i will give up
before i break a rib
Words and Feathers 
This is a nice twist on the two-hearted time lord Dr. Who. Beautifully reasoned and elegantly executed.
Thanks. The Dr. Who thing was definitely on my mind. š
Great opening line.
Thank you!
Your poor ribcage – absolutely love the concept of needing a heart for each time period.
Thanks!