Barth begins by repeating his claim that Jesus Christ is the foundation of all God's ways and works. "He is the decree of God behind and above which there can be no earlier or higher decree and beside which there can be no others, since all others serve only the fulfilment of this decree. He is the beginning of God before which there is no other beginning apart from that of God within Himself" (94). It would be futile to look for any more basic determination of God in his ways and works than the man Jesus Christ. Barth backs this up with an exegesis of John 1:1-2, in which he argues that it is precisely Jesus Christ who was with God in the beginning. I am not sure how convincing I would find this by itself, but as Barth points out it merely reflects an idea "which is quite familiar in the witness of the New Testament" (98), citing amongst others Colossians 1:15 and Hebrews 1:3.
The doctrine, then, is pushing is back into the sphere of who God is in himself, in his eternal self-being. But Barth warns us against thinking that "this sphere is empty and undetermined" (100), or occupied only by an abstract god-image defined by absolute choice. "In terms of the doctrine of election, that would leave us with an absolute decree, the danger of which he has already discussed. Rather, we are to think already of Jesus Christ. "In the beginning, before time and space as we know them, before creation, before there was any reality distinct from God which could be the object of the love of God or the setting for His acts of freedom, God anticipated and determined within Himself... that the goal and meaning of all His dealings with the as-yet non-existent universe should be the fact that in His Son He would be gracious towards man, uniting Himself with him" (101).
That Jesus Christ is both the one who elects and the one who is elected reflects the fact that he is both God and man. That Jesus Christ is the electing God means that he takes the place of the absolute decree - we are not dealing with an abstract God, but with Jesus. Jesus Christ was in the beginning with God, not just in the way that all creation was in God's plan, but as himself God. "Thus Jesus Christ is not merely one object of the divine good pleasure side by side with others. On the contrary, He is the sole object of this good pleasure, for in the first instance He himself is this good pleasure, the will of God in action" (104). Barth argues that Augustine saw the importance of this - as did Athanasius (he cites from the second Oration against the Arians, esp. 75-77). The point is that "Jesus Christ is the electing God. We must not ask concerning any other but Him. In no depth of the Godhead shall we encounter any other but Him", which has the pastoral implication that "in the very foreground of our existence in history we can and should cleave wholly and with full assurance to Him, because in the eternal background of history, in the beginning with God, the only decree which was passed, the only Word which was spoken and which prevails, was the decision which was executed by Him" (115).
Jesus Christ is also elected man, which means that "before all created reality, before all being and becoming in time, before time itself, in the pre-temporal eternity of God, the eternal divine decision as such has as its object and content the existence of this one created being, the man Jesus of Nazareth, and the work of this man in His life and death, His humiliation and exaltation, His obedience and merit" (116). It is not that the man Jesus of Nazareth is worthy of this - he does not exist! Rather, "in the predestination of the man Jesus we see what predestination is always and everywhere - the acceptance and reception of man only by the free grace of God" (118). Note that Barth is saying more here than that Jesus is the first example of election; he is saying that in the election of this man is encompassed God's will for all creation. "This man Jesus, as the object of the divine decree, is the beginning of all God's ways and works, the first-born of all creation (121).
And this election has shape: "the elected man Jesus was foreordained to suffer and die" (122). Because the election of Jesus carries within itself the election of a creation free from sin and free for God, it is a predestination to the cross. "The rejection which all men incurred, the wrath of God under which all men lie, the death which all men must die, God in his love for men transfers from all eternity to Him in whom He loves and elects them, and whom He elects as their head and in their place" (123). "He did not owe it to us to do it. For it was not He but we ourselves in our culpable weakness who delivered us up to Satan and to the divine wrath and rejection. And yet God does it because from all eternity He loves and elects us in His Son, because from all eternity He sees us in His Son as sinners to whom He is gracious" (125).
If Jesus is the elect man, what does that mean for individuals? Granted that Barth thinks it would be disastrous to start with this question, we presumably do have to ask it at some point. And here we get a hint of his answer: "their election consists concretely in their faith in Him" (126). "To believe in Jesus means to have His resurrection and prayer both in the mind and in the heart. And this means to be elected" (127). Which I understand descriptively, and I can see the pastoral wisdom in directing people to trust wholly in Christ as the one who is Elect. But there is still that nagging question: why do some believe and not others? We'll see whether it gets addressed or not; Barth might think it an irrelevant question.
The sub-section closes with a (somewhat lengthy) historical review of the supralapsarian/infralapsarian debate of the 17th century. For what it's worth, Barth comes down more on the supra side, whilst pointing out that on his own presuppositions both systems are inadmissible due to their fault presupposition of an absolute decree and therefore a somewhat balanced system of election and reprobation. If only, he thinks, they had all started with Jesus.