Explain SMBC — the wiki for Saturday Morning Breakfast Cereal

This single-panel comic is titled "Execution Strategy: Try to say the most disconcerting thing possible before you die." A man with his head in a guillotine shouts "The cure for cancer is--" just as the blade is presumably about to fall, cutting off his sentence (and his head) before he can finish.

The humor lies in the idea that this would be the most psychologically tormenting thing a condemned person could do to the onlookers -- begin revealing world-changing, life-saving information and then die before completing the sentence. The witnesses would be left forever wondering whether he actually knew the cure for cancer or was just trolling them. It is a darkly comic take on the concept of famous last words, turning the condemned person's final moment into a masterful act of psychological warfare against the audience.