Read "Some Blind Eidolon" at The Eldritch Dark:
This poem from Clark Ashton Smith (CAS) uses a variation on the Spanish septet form (aka the septilla) with the fourth line being repeated as the seventh line. I've never seen this specific form before, so I'm assuming it might have been CAS' own invention.
The work opens with an ominous declaration: "I chose for mine / The love whereto some ancient evil clings". And of course, nothing good can come from such a start:
The stain that creeps unstayed
In love's alloy?
The fretful moth that frays the bed of lust?
Such goings on lead to hints of doom:
Where the self-deluded mourner sobs alone
Amid the ruined flowers and the founts.
"Some Blind Eidolon" does not end on a happy note - the two lovers are apparently bound together in an immortality with no prospect of escape:
Shall make us one in its potential deep—
Washing the lethal dross of self away—
What sea wherein the unshapen planets sleep?
This is quite a dark poem from the pen of CAS, reminiscent of his youthful verses of cosmic doom and malevolent forces on a grand scale.