Harry Desperately Tries to Cling to Sirius
On the last evening of school, Harry is packing when he notices the unopened gift that Sirius had given him - a [two-way mirror] to use in case he needed to contact Sirius. After a failed attempt at using the mirror, he gets another idea instead and rushes downstairs.
The Journey Home
Harry stands alone outside the [Great Hall] when Luna walks up, and they talk for a bit about Sirius and about [Luna's mother]. Inexplicably, the conversation makes Harry feel a bit better, even as Luna walks away.
The trip home on the [Hogwarts Express] is uneventful, aside from Malfoy, Crabbe, and Goyle getting transformed into slugs by members of the D.A. when they try to attack Harry. Although, Harry does learn that Cho is dating [Michael Corner], and Ginny [Dean Thomas] (drawing a reaction from Ron).
Back at [Kings Cross] once again, Harry is made to feel better by his guard of Moody, Tonks, Lupin, the Weasleys, and the [twins], who threaten the [Dursleys] to take good care of him over the summer. Finally, Harry walks off, Dursleys in tow, ready to face another summer.