What happened in the ending of Tomb Raider Underworld?

At the end of Tomb Raider: Underworld, Lara Croft defeats Natla, the main antagonist, and retrieves the Scion of Atlantis, a powerful artifact. She then escapes the collapsing temple with the help of her friend, Zip.

Lara returns to her home in England and reunites with her butler, Winston. She gives the Scion of Atlantis to the British Museum, where it is kept for safekeeping.

Lara then reflects on her adventures and realizes that she has become a true tomb raider. She knows that there will be more adventures in her future and that she is ready for them.