To illustrate the retrograde, I will use the planet Mars as an example. This explanation can be applied to the other planets as well, the only difference will be the events. Mercury affects communication; Venus affects relationships and money; Mars brings events such as fires and war; Jupiter affects religion, philosophy and foreigners; Saturn affects structure and authority and brings loss and delays; Uranus brings unexpected, rebellious events, Neptune brings disillusion and fantasy, as well as visions and mysticism, and Pluto brings destruction of those things that no longer serve us.
Go back in time to the middle ages. You are the court astrologer for a famous warrior king. You have noticed that the planet Mars has been acting odd; it has been slowing down and sort of hanging over the castle. In the past, this has always been a sign of war. You fear dire things are ahead, but the king is ill, confined to his bed, the second in charge is away, and you fear that the castle will soon be besieged. The slowing down of Mars, a warning phase, is the shadow phase.
You keep looking at the sky, and about six weeks later, you see that Mars has stopped moving. You and the inhabitants of the castle are like sitting ducks, no one has listened to you, and sure enough, there is an army of invaders outside the gates. When Mars stops in the sky this is the station retrograde.
A few days later Mars starts to move again, but in the other direction. The invaders now start moving toward the castle, and you feel helpless; you have to convince everyone to do the best they can to hold back the invaders, and you retreat further into the castle away from the invaders. This backward movement is called the retrograde.
Let’s move ahead in time. The invaders have been trying to storm the castle for over two months. The King is now yelling and cursing, especially at you, saying he will chop off your head if things don’t change. You keep telling him that the problems will soon be over. Once again you have noticed that Mars is slowing down, this is the signal that it’ll soon go back to normal. Mars fulfilled its promise, everything was held back; the invaders weren’t repelled, but they didn’t get in, but now they have brought in a battering ram. The heat is on, and the battle is getting intense.
A few nights’ later you go up on the ramparts and notice that Mars has finally stopped; it’s just sitting there. This is the station direct. The retrograde phase is over, the tables are about to turn. Sure enough, off in the far distance you see the allies of the king coming to rescue him, just in time. The invaders are rooted out, and your head is safe for now.
Now all there is to do is to clean up the mess, heal the wounded, speed the recovery of the king with new supplies and medicines, and repair the damage to the castle. This is the second shadow phase, and when this is over the success of military maneuvers will resume without struggle. That is the end of the retrograde and the war.