It was the worst of times, it was the worst of times.

Spearman said it first. RickyD repeated it shortly thereafter. I suppose it fits here too:

"Crack Kills!

Alas, the Beast—this Beast, my Beast—is no more. My Cross-check MC Sekai has checked out, given up the ghost, bought the farm, bit the dust, kicked the bucket, taken a dirt nap, shuffled off this mortal coil, run down the curtain, joined the choir invisible, cashed in its chips, hung up its spoon, had its ticket punched, sung its chant du cygne, earned its wings, gone tits up.

It is finished."

I contacted Baltimore-based framebuilder/framerepairer Tom Palermo at Palermo Bicycles (Flickr group here) and asked about the chances of recovery for my cracked-out Sekai frame. Sadly, the prognosis is not good. Tom says:

"It's repairable but it's a pretty involved/expensive job. It looks
like the top tube is cracked as well as the lug. So, you're looking at
a top tube replacement, which is major surgery... at least $200.
Personally, I wouldn't spend the money to do that. You can probably find another used frame for what it would cost to repair this.