Mich. Comp. Laws § 767.26

Sec. 26. Any person held in prison on any charge of having committed a crime, shall be discharged if he be not indicted before the end of the second term of the court at which he is held to answer unless it shall appear to the satisfaction of the court that the witnesses on the part of the people have been enticed or kept away, or are detained and prevented from attending the court by sickness or some inevitable accident, and except in the case provided for in the next section.