Original: This client, who is actually Jack the Ripper, murders Lulu, and then on his way out kills the Countess as well, who swears her love to Lulu as the curtain falls.
Simplified: This client, who is actually Jack the Ripper, murders Lulu, and then on his way out kills the Countess as well, who swears her love to Lulu as the curtain comes down.