"With ordinary means, there is no way to contact them anymore... unless we send them a letter by owl. But..." old Tom said with a troubled expression.
In the current Muggle world, technology was not yet advanced enough. Even though Britain was so close to France, traveling back and forth plus communicating still took a fair amount of time. Fortunately, owls were available now to deliver letters to them in a timely manner, but...
By the time they received the letter...
Chapter 191