I don't know if Michael is a Catholic or not, but a Catholic can marry a baptized non-Catholic and receive the sacrament of marriage. The non-Catholic would need to be a Christian and agree to bring up the children in the Catholic faith.
Once the couple is married in the Catholic Church, a divorce is not recognized by the Church, only annulments.
If a couple wants to marry in the Catholic Church and one spouse has been married before, the rule is if they were legitimately married in a Christian Church, then they cannot marry in the Catholic Church if the divorced spouse is still alive. If it is a civil marriage and divorce, then that person can still marry in the Catholic Church, if the spouse is alive.