What is an objective summary of the events in Act 1, Scene 1 in Shakespeare's play Richard 111?

Richard gives a short speech detailing his plot against his brother Clarence, who comes before him as heir to the throne of England. Richard has just succeeded in having Clarence arrested and it as a prisoner that Clarence walks onto the stage, guarded by Sir Robert Brackenbury.

Richard asks Clarence what the reason for his arrest is. Clarence replies that someone told King Edward that a person with a name starting with the letter "G" would cause his family to lose the throne. Since Clarence's full name is George, Duke of Clarence, he was considered to be the primary suspect. Richard complains that this arrest is the result of the women plotting against Clarence, most notably Queen Elizabeth and possibly also Mrs. Shore.

Brackenbury tells the men he is not allowed to let anyone converse with the prisoner, and takes Clarence into the Tower of London. Richard comments that he will soon remove Clarence permanently and thus clear the path to the throne for himself.

Lord Hastings, also known as Lord Chamberlain, emerges from the Tower, having just been freed. Lord Hastings tells Richard that King Edward IV is sickly and ailing, and cannot hope to live much longer. After he departs, Richard remarks that he will first have Edward kill Clarence. This will put Richard into a position where upon Edward's death he can assume the throne. He also plots to marry Lady Anne Neville, who is the widow of Edward, Prince of Wales and the daughter-in-law of Henry VI, whom Richard just killed.