Turnus and his allies are having huge success rounding up local recruits against the foreign invaders. They also send out emissaries to the Greek hero Diomedes (famous from Homer's Iliad), trying to convince him to take up the fight against his old enemies, the Trojans.
Aeneas has a pretty good idea of what's going on, and is deep in thought about what to do about it. All that thinking makes him tired, though, and so he falls asleep.
In his sleep, Aeneas sees Tiberinus – the god of the River Tiber – appear before him.
Tiberinus tells him that the gods aren't mad at him anymore, and that he shouldn't be afraid of the war to come.
Then he says, "In case you think this is only a dream, you're going to find under some trees by the shore a white sow nursing thirty piglets; this will mean that after thirty years Ascanius will found a city called Alba." (The name of the city means "White." Tiberinus is echoing the prophecy made to Aeneas in Book 3.)
Next, Tiberinus gives Aeneas some helpful advice. He tells him to go to the nearby kingdom of the Arcadians – a Greek tribe – ruled by a dude named Evander. He says that these guys are always at war with the Latins; Aeneas should bring them on his side.
Finally, he tells Aeneas to pray to Juno, to try to win her over. (Fat chance.)
Aeneas wakes up, gives thanks to the god, and then orders his men to make ready two ships.
But just then, he catches sight of the white sow and her litter…and decides to sacrifice them to Juno. (Sorry, animal lovers.)
Then Tiberinus makes the waters of the River Tiber perfectly still, so the ships can sail easily to the settlement of the Arcadians.
The Arcadians are making sacrifice to Hercules; when they see the Trojans arrive, King Evander's son Pallas runs down to ask them who they are.
Aeneas explains his mission and Pallas invites them to dine with his family that night.
Then Aeneas approaches Evander and says, "I know you're Greek and I'm Trojan, but hey; your people and ours are connected by some fancy-shmancy genealogical stuff from way back. Anyway, we've got a common enemy now: the Latins. Let's make war on them together."
Evander says, "No worries. I met King Priam once. He was a cool guy. When you leave tomorrow, I'll give you some troops. But as for right now, it's party time."
After they are done eating a succulent feast on the grass, Evander points to a collapsed cave on the side of a nearby mountain, and starts telling them all a story.
It turns out that it used to be inhabited by a half-beast half-man guy named Cacus. His name means "Bad" in Greek, and he sure lived up to it, killing lots of people and walking around belching fire. (The last part is because his dad was Vulcan, the god of fire.)
Then Evander explains that Hercules came and kicked Cacus's butt. In the process, he ripped out the side of the mountain, because Cacus was hiding inside. That's why the Arcadians now worship Hercules as their special god.
When the feast is done, they continue their rituals. The Salii, a certain class of priest, come in and start dancing and worship Hercules. They then sing a song about the hero.
After dinner, they walk back to the city. Evander walks with Aeneas and tells him about how the land used to be in ancient times, before generations of people screwed it all up.
Then he shows them various sites – sacred grottoes and the like – that Virgil explains will be important in later Roman history and myth.
When they get to Evander's settlement – the future site of Rome – the King tells Aeneas to make himself at home in his humble surroundings. He does, and goes to sleep.
Meanwhile, Venus, lying in bed beside her husband Vulcan, is troubled by what's going on. Putting on her most seductive voice, she convinces him to make some nifty armor for Aeneas.
Then Vulcan gets it on with Venus, gets a little shut-eye, gets up, and gets to work.
In the meantime, morning rolls around, and Evander wakes up and heads outside, accompanied by his son, Pallas. He finds Aeneas, accompanied by Achates, and they sit down for a conversation.
Evander tells Aeneas that the Arcadians themselves are not going to be strong enough allies against Turnus and company.
He says, though that the nearby Etrurians might be able to help. They were once ruled tyrannically by Mezentius – now an ally of Turnus – until they kicked him out.
There are thousands of them ready for action, only they are held back by a sign that says they should only go to war under a foreign commander. (Hint, hint?)
Enough beating around the bush. Evander says that Aeneas should command the Etrurians, plus a contingent of Arcadians. He also says that he is going to send his son, Pallas, along with him, so he can learn the ways of war.
When Evander is done speaking, they hear a lot of booming and clattering in the heavens. Aeneas says, "Don't worry. It's just my mom telling me my armor is ready." (Kind of like an ancient version of the dinner-gong.)
Evander and Aeneas now make the proper sacrifices, and get things in order. Some riders are going to get the Etrurians; a ship is heading back down the Tiber to let Ascanius know what's up, and Aeneas is choosing followers from among the Arcadians.
Before they head out, Evander takes Pallas aside and tells him how he wishes he were young and could go in his stead. He prays to the gods to protect him.
Then they ride out.
On their way, they are met by Venus, who approaches Aeneas and gives him the weapons made by Vulcan.
Aeneas admires the armor, especially the shield, on which Vulcan has fashioned many scenes from future Roman history.
These include scenes from right before the time when Virgil was writing – such as of Caesar Augustus's defeat of the allied forces of Marc Antony and Cleopatra.
Even though he doesn't know what they mean, Aeneas likes the pretty pictures, and picks up the shield.