Who keeps Odysseus captive for 7 years?
The goddess Calypso of Ogygia holds Odysseus captive on her island for 7 years. During the time he spends with her, Calypso falls in love with Odysseus (of course she does; he's an Epic Hero!) and desires that he remain with her on the island, "she keeps on coaxing him with her beguiling talk, to turn his mind from Ithaca," (Book 1, lines 77-78).
Athena speaks to her father, Zeus, on Odysseus's behalf and requests that he set Odysseus free. "O Majesty, O Father of us all, if it now please the blissful gods that wise Odysseus reach his home again, let the Wayfinder, Hermes, cross the sea to the island of Ogygia; let him tell our fixed intent to the nymph with the pretty braids, and let the steadfast man depart for home," (Book I, lines 106-112).
Wanting to keep his daughter happy, Zeus agrees and dispatches Hermes to deliver the news to Calypso."Now the command is: send him back in haste. His life may not in exile go to waste. His destiny, his homecoming, is at hand, when he shall see his dearest, and walk on his own land," (Book V, lines 118-121).
Calypso is very upset by the decree, as she doesn't want to set Odysseus free, and she believes she deserves his company because she saved him. She also offered him immortality: "I fed him, loved him, sang that he should not die nor grow old, ever, in all the days to come," (Book V, lines 142-143). She continues to try to find excuses as to why she can't send him on his way, but Hermes ignores her pleas and warns that she follow Zeus's order or be punished by Zeus forever. "Thus you shall send him, then. And show more grace in your obedience, or be chastised by Zeus," (Book V, lines 153-154)
When Calypso tells Odysseus he is free to go, he believes it is a trick, because she has never offered him this opportunity before. However, she assures him that he will be sent off with necessary provisions and a helpful wind. Before he returns to his loyal wife and his homeland; however, Calypso wants Odysseys to assure her that his wife is not more beautiful than she, "Can I be less desirable than she is? Less interesting? Less beautiful? Can mortals compare with goddesses in grace and form?" (Book V, lines 220-223).
Odysseus draws on a few of his epic hero qualities (i.e. suavity, diplomacy, tact) to answer her without offending her, "My lady goddess, here is no cause for anger. My quiet Penelope--how well I know-- would seem a shade before your majesty..." (Book V, lines 226-227). As she is satisfied with his response, Calypso sets Odysseus free, keeping her promises to send him with provisions and a strong wind.