Somewhere close to Harrenhal... The main objective of Lord Tywin is to protect the King. He is the Lord Hand, and as such, will make every effort necessary in doing so. Harrenhal stands in the way. Lord Tywin and Addam Marbrand had set out to take control of the castle, only to be met with a wall of Tully forts. Attempting to bypass them, Tywin sent Addam and a small scout team ahead. He spotted Tytos Blackwood and engaged.
With the path presumably clear, Tywin began his march around the forts to Harrenhal. By surprise, he was attacked by Ser Brynden Tully. Being ever so cunning, Tywin kept a much larger host with him. He was able to force defeat on his enemy.
The men needed rest. It was there, they stopped and made camp. Their march will continue in a few weeks, after wounds have healed.
Realizing the delay his enemies caused, he sent word to Lancel to come from south of Harrenhal. Lancel was asked to muster all the men he could. Unfortunately for the unappreciated lord, he was only able to take his cousin, Tyrek, and a few dozen bodyguards. Marching north, he and his men stopped to set camp for the night. Out of the forest came another Tully ambush. A few were left dead, but Lancel and Tyrek finished the march back to his their uncle's camp in record haste.