"Hour of Arrival" is a letter from a high-ranking government worker to his unborn child (Danny if it's a boy, Jane if it's a girl). He talks about his wife's sister, Chrissy and his own childhood. He also offers some advice to the child and what he would like to do together. Along with these writings are reports of The Presence being spotted in cities around the world, even Washington, DC. The letter is cut off at the end.
The letter is connected to The Beginning Of The End, quoting "This is the beginning" in the ending of the letter before the cutoff.
The number 24.4.1 was found on this page.