Romeo was angered by the fact that Tybalt killed one of Romeo's best friends Mercutio and then killed him in a battle for revenge.
Bad News To Romeo
In this scene Juliet is taking desperate measures to not marry Paris,she convinces Apothecary to give her a vile of poison and fakes her death in her room when she is alone,the nurse and Lady Capulet attempt to wake her and come to the thought that she is dead.
Romeo's Downfall
The entirety of the plans for the wedding are cancelled and turned over to a funeral for the Capulet's in the tomb where Julie is put to rest,the family still believing she is really dead when she has only faked it to get away from Paris and pursue her life with Romeo as she wanted.
The Final Moments Together
Romeo receives letter from his servant Balthasar which notifies him of Juliet's "passing",without knowing of it all being a fake,Romeo is full of dread thinking his true love has passed.
Romeo with his mind full of dread and misery also convinces Apothecary for a vile of poison,planning to end himself right next to Juliet in the Capulet tomb,planning to sneak in without anyone knowing and drinking the vile.
After sneaking into the Capulet Tomb,Romeo is confronted by Paris who is hiding there,they end up in a fight and Romeo ends victorious but with the cost of Paris being killed,Romeo then stands next to Juliet and drinks the vile,falling dead on top of her,Juliet awakes and is shocked by losing her loved one,mourning the loss of Romeo,she stabs herself,both lovers dying together.