When Saturn joins the nodes, there is a pretty strong alignment of stressful energy.
Rahu/Saturn could be quite a difficult placement, sort of like when Mars joins the nodes. Rahu and Saturn are both planets of fear. Rahu is our imagined fears and the kind of stress in life and worry that we are wasting time.
Rahu / Ketu and Saturn
Saturn is actually the stress and worries of the tangible life — the things that pressure us. When we get Rahu/Saturn together, we often feel this pressure of time both in a tangible and intangible ways.
Saturn is where we need to learn to cultivate solitude and go into our true self beyond the world of time. This stress and pressure of external time is there to compel us to go deeper into that timeless or formless state. We stress out over the forms that will change but internally, the formless will never change.
As Saturn matures, that worrying about external structures becomes a great competency of committing to the internal structure. Rahu will eventually make us aware of all these but it can be very stressful because whatever Rahu joins, he excites. This will be a very accelerated, stressful placements at times.
Ketu/Saturn can also have the feeling of stress but there can be a lot more mastery of that area of life. Actually, wherever Ketu is, there is a certain amount of mastery already there because the soul has a lot of experience with that thing.
With Ketu/Saturn, we have experienced the pressure in life a lot. We realize that this is the quality of life that we need to really master and rather than obsessing over the outer form, we need to go inward and conquer that inner fear.