It's worse that I thought.
After rest/ice on the achille's tendon for the past week, I attempted a ride sunday morning. It went from feeling absolutely no pain or discomfort in the past few days to a searing, stabbing sensation in less than 20 minutes. This was spinning an easy gear (39x16) with no hills.
Now it's a day later and it's painful to walk up stairs again. I'll be calling my doctor this morning.