Before Agrippina went to her island he had her before him and asked her mocking questions about how

Before Agrippina went to her island he had her before him and asked her mocking questions about how she proposed to govern the mighty kingdom which she had just inherited from her mother (his virtuous late wife), and whether she would send ambassadors to her son, Nero, in his new kingdom, and enter into a grand military alliance with him. She did not answer a word. He grew angry and roared at her to answer, and when she still kept silent he told a captain of the guard to strike her over the shoulders. Then at last she spoke. "Blood-soaked Mud is your name. That's what Theodoras the Gadarene called you, I'm told, when you attended his rhetoric classes at Rhodes." Tiberius seized the vine branch from the captain and thrashed her about the body and head until she was insensible. She lost the sight of an eye as a result of this dreadful beating.
Soon Drusus too was accused of intriguing with the Rhine regiments. Sejanus produced letters in proof, which he said that he had intercepted, -but which were really forged, and also the written testimony of Lepida, Drusus's wife (with whom he had a secret affair), that Drusus had asked her to get in touch with the sailors of Ostia, who, he hoped, would remember that Nero and he were Agrippa's grandsons. Drusus was handed over by the Senate to Tiberius to deal with and Tiberius had him confined to a remote attic of the Palace under Sejanus's supervision.
Callus was the next victim. Tiberius wrote to the Senate that Callus was jealous of Sejanus and had done all that he could to bring him into disfavour with his Emperor by ironical praises and other malicious methods. The Senate were so upset by the news of the suicide of the Recorder, which reached them the same day, that they immediately sent a magistrate to arrest Callus. When the magistrate went to Callus's house he was told that Callus was out of the City, at Baiaa. At Baiaa he was directed to Tiberius's villa and, sure enough, he came on him there at dinner with Tiberius. Tiberius was pledging Callus in a cup of wine and Callus was responding loyally, and there seemed such an air of good humour and jollity in the dining-hall that the magistrate was embarrassed and did not know what to say. Tiberius asked him why he had come. "To arrest one of your guests, Caesar, by order of the Senate."
"Which guest?" asked Tiberius. "Asinius Callus," replied the magistrate, "but it seems to be a mistake." Tiberius pretended to look grave; "If the Senate have anything against you, Gallus, and have sent this officer to arrest you, I'm afraid our pleasant evening must come to an end. I can't go against the Senate, you know. But I'll tell you what I'll do, now that you and I have come to such a friendly understanding: I'll write to ask the Senate, as a personal favour, not to take any action in your case until they hear from me. That will mean that you will be under simple arrest, in the charge of the Consuls-no fetters or anything degrading. I'll arrange to secure your acquittal as soon as I can."
Gallus felt bound to thank Tiberius for his magnanimity, but was sure that there was a catch somewhere, that Tiberius was paying back irony with irony; and he was right. He was taken to Rome and put in an underground room in the Senate House. He was not allowed to see anyone, not even a servant, or send any messages to his friends or family. Food was given him every day through a grille. The room was dark except for the poor light coming through the grille and unfurnished except for a mattress. He was told that these quarters were only temporary ones and that Tiberius would soon come to settle his case. But the days drew on into months, and months into years, and still he stayed there. The food was very poor-carefully calculated by Tiberius to keep him always hungry but never actually starving. He was allowed no knife to cut it up with, for fear he might use it to kill himself, or any other sharp weapon, or anything to distract himself with, such as writing materials or books or dice. He was given very little water to drink, none to wash in. If ever there was talk about him in Tiberius's presence the old man would say, grinning: "I have not yet made my peace with Gallus."