Hello This is an extract of Love letters by Katie Fforde. The girl is visiting Ireland to meet an eccentric writer. The owner of the guesthouse advised her not to go to his house but at the same time she also wants her to find out if the man is alright or not. "If he turns on you, you can fly back to England." "Should I have a taxi with its engine running outside?" Laura was laughing too now. "No, but I'll get Murphy to keep his mule on stand-by." Please explain to me the last sentence. Thanks.