Saturn and Pluto join up in a similar part of the zodiac every years. This is because 25 Saturn orbital periods is approximately equal to 3 Pluto orbital periods. Here is my poorly done illustration of this cycle. Believe it or not, one major reason you should not freak out about this transit is that it can only be significant for certain areas of your life, some more central, others more peripheral. In some cases, there may be parts of your life, even large parts, which are largely unaffected by this transit.
There are at least 3 ways to understand what significance this transit may have in your own life. A What area of life is this transit significant for, and does it even apply to you? Everyone has an Ascendant in a particular sign, and the relationship of those signs to the Ascending sign and nearest angle is what gives each of those signs a particular relevance for a specific topic in your life. This is also known as the whole sign house system.
So depending on where Capricorn was relative to the horizon at the time you were born will tell you something about the area of life this transit will have significance for.