Read ancient literature. You should read the plot beforehand. The storylines of ancient literature are designed to be enjoyed by people who already know how they end.

Achilles kills Hector but gives his body back.

Aeneas kills Turnus in an uncharacteristic anger that undermines his integrity as a protagonist.

Croesus' empire is overtaken by Cyrus. Croesus becomes Cyrus' advisor. Turns out Solon was right.

Caesar beats Vercingetorix and all the other Gauls too.

Beowulf and the dragon both die.

Jesus comes back to life at the end.

Reject novels. Novels are a dumb form of literature, anyway. Embrace tradition. Read war poetry.