When Telemachus reaches Eumaeus’s hut, he finds the swineherd talking with a stranger (Odysseus in disguise). Eumaeus recounts Odysseus’s story and suggests that the stranger stay with Telemachus at the palace. But Telemachus is afraid of what the suitors might do to them. Eumaeus thus goes to the palace alone to tell Penelope that her son has returned.
When father and son are alone in the hut, Athena appears to Odysseus and calls him outside. When Odysseus reenters the hut, his old-man disguise is gone, and he stands in the pristine glory of his heroic person. At first, Telemachus cannot believe his eyes, but then the two embrace and weep. Odysseus recounts his trip with the Phaeacians and then begins plotting the overthrow of the suitors. He formulates a plan to launch a surprise attack from within the palace: Odysseus will enter disguised as a beggar and Telemachus will hide the palace’s surplus arms where the suitors cannot easily reach them. The two of them will then seize the arms and slaughter the suitors.
Before Eumaeus can give Penelope news of Telemachus’s return, the messenger from the ship arrives and informs the entire palace that Telemachus has returned. The suitors, dejected that their plot has failed, huddle outside to plan their next move. Antinous recommends putting Telemachus to death before he can call an assembly at which the suitors’ dirty schemes can be aired, but Amphinomus, one of the more thoughtful and well-behaved suitors, persuades the others to wait for a sign from the gods before doing anything so rash. Penelope later finds Antinous in the palace and denounces him for the plot against her son, the details of which Medon had overheard and revealed to her in Book 4. Eurymachus succeeds in calming Penelope down with his lies and false concern for the safety of Telemachus.
This Book contains the long-awaited reunion of Odysseus and Telemakhos. Homer doesn't make that much of the event, however - it seems to be generally less important than the reunion of Odysseus and Penelope.
This is not to say that the father/son relationship is de-emphasised in the Book. Telemakhos tells Odysseus that he has heard of his kleos. He also indicates that he has inherited something of Odysseus' intelligence when he suggests a minor amendment to Odysseus' plan - he should not waste time by investigating the loyalty of his male retainers.
Telemakhos gives a clear statement of the patriarchal succession in Odysseus' household:
"For Kronos' son has given us this one family line:Telemakhos still seems to lack the confidence to fully step into the role of master of the house, however.
Arkeisios begat Laertes as his only son;
he then fathered Odysseus as his only son; and he
begat me alone and left me in his halls...."
Interestingly, Eumaios is said to greet Telemakhos like a father who has been separated from his son for 10 years, and Telemakhos refers to him as "atta" (meaning roughly "father").
We see Penelope emerging as a substantial figure, castigating Antinoos for plotting against Telemakhos.