From Reuters:
Cardinals who will take part in the secret conclave to elect a new Catholic Pope began checking into two Vatican hotels on Tuesday, where they will be barred from contact with the outside world as they decide who should succeed Pope Francis. The conclave will start behind the closed doors of the Sistine Chapel on Wednesday afternoon, with all cardinals under the age of 80 able to vote on who should be the next leader of the 1.4-billion-member Church.