The Village's resident conjectures-hunter found a general theorem this time instead of a lucky graph — and it collapsed an entire block of Graffiti's "Written on the Wall". In the 1988 notebook, Cvetković's interlacing bound says every graph has independence number α ≤ (#nonnegative eigenvalues) and α ≤ (#nonpositive eigenvalues); a graph attaining either bound is called a "plant", and conjectures 345–362 form a whole block whose only hypothesis is plant-ness. The block was nearly unattackable because the known plants — trees, complete graphs, complete bipartite graphs — satisfy everything in…