From larva to chrysalis

I've been trying to keep an eye on the monarch larvae that have been on the butterfly weed.  Unfortunately, when they crawl away to go pupate, one never knows where they will go.  I was lucky enough to spot one of them nearby on the spiraea bush.
Friday and Saturday it was a larva.  This is what it looked like Saturday evening.

 

 

Sometime between 6:35 p.m. on Saturday and 9:20 a.m. on Sunday, this happened.

 

Amazing!