The Landgrave of Hesse-Cassel was next summoned by Tilly, who threatened to carry fire and sword through his dominions unless he would immediately disband his troops, pay a heavy contribution and receive the Imperial troops into his cities and fortresses; but the landgrave refused to accept the terms.
Owing to the unhealthiness of the district round Old Brandenburg, Gustavus raised his camp there, and marched forward to Werben near the junction of the Elbe with the Havel.

He was joined there by his young queen, Maria Eleonora, with a reinforcement of 8000 men, and by the Marquis of Hamilton with 6200, for the most part Scotch, who had been raised by him with the consent of Charles I, to whom the marquis was master of the horse.
Werben was distant but a few miles from Magdeburg, and Pappenheim, who commanded the troops in that neighbourhood, seeing that Gustavus was now in a position to take the field against him, sent an urgent message to Tilly for assistance; and the Imperial general, who was on the point of attacking the Landgrave of Hesse-Cassel, at once marched with his army and effected a junction with Pappenheim, their combined force being greatly superior to that of Gustavus even after the latter had received his reinforcements.
Malcolm had not accompanied the army in its march from Old Brandenburg.
He had been prostrated by fever, and although he shook off the attack it left him so weak and feeble that he was altogether unfit for duty.
The army was still lying in its swampy quarters, and the leech who had attended him declared that he could never recover his strength in such an unhealthy air.

Nigel Graheme, who had now rejoined the regiment cured of his wound, reported the surgeon's opinion to Munro.
"I am not surprised," the colonel said, "and there are many others in the same state; but whither can I send them?
The Elector of Brandenburg is so fickle and treacherous that he may at any moment turn against us." "I was speaking to Malcolm," Nigel replied, "and he said that he would he could go for a time to recruit his health in that village among the hills where he had the fight with the freebooters who made him captive.
He said he was sure of a cordial welcome there, and it is but three days' march from here." "'Tis an out-of-the-way place," Munro said, "and if we move west we shall be still further removed from it.

There are Imperial bands everywhere harrying the country unguarded by us, and one of these might at any moment swoop down into that neighbourhood." "That is true; but, after all, it would be better that he should run that risk than sink from weakness as so many have done here after getting through the first attack of fever." "That is so, Nigel, and if you and Malcolm prefer that risk to the other I will not say you nay; but what is good for him is good for others, and I will ask the surgeon to make me a list of twenty men who are strong enough to journey by easy stages, and who yet absolutely require to get out of this poisonous air to enable them to effect their recovery.

We will furnish them with one of the baggage wagons of the regiment, so that they can ride when they choose.