Generally speaking, you'll get a complaint just before the answer is due, and you'll need to whip out an answer, then gather the facts and file an amended answer (you get 1 amendment without leave of the court).
And another thing: always ask your client what they want to accomplish. Winning on the merits is different from paying less than $0.5M which is different from having these four people deposed. Knowing the client's true objectives allows you to serve them better.